Term
| How does the process of science start and end? |
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Definition
| Science begins with curiosity and often ends with discovery. |
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Term
| What is the relationship between science and technology? |
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Definition
| Science and technology are interdependent. Advances in one lead to advances in the other. |
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Term
| What are the branches of natural science? |
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Definition
| Natural science is generally divided into three branches: physical science, Earth and space science, and life science. |
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Term
| What is the goal of a scientific method? |
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Definition
| The goal of any scientific method is to solve a problem or to better understand an observed event. |
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Term
| How does a scientific law differ from a scientific theory? |
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Definition
| A scientific law describes an observed pattern in nature without attempting to explain it. The explanation of such a pattern is provided by a scientific theory. |
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Term
| Why are scientific models useful? |
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Definition
| Scientific models make it easier to understand things that might be too difficult to observe directly. |
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Term
| Why is scientific notation useful? |
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Definition
| Scientific notation makes very large or very small numbers easier to work with. |
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Term
| What units do scientists use for their measurements? |
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Definition
| Scientists use a set of measuring units called SI, or the International System of Units. |
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Term
| How does the precision of measurements affect the precision of scientific calculations? |
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Definition
| The precision of a calculated answer is limited by the least precise measurement used in the calculation. |
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Term
| How do scientists organize data? |
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Definition
| Scientists can organize their data by using data tables and graphs. |
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Term
| How can scientists communicate experimental data? |
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Definition
| Scientists can communicate results by writing in scientific journals or speaking at conferences. |
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Term
| Why are elements and compounds classified as pure substances? |
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Definition
Every sample of a given substance has the same properties because a substance has a fixed, uniform composition.
An element has a fixed composition because it contains only one type of atom. |
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Term
| How do mixtures differ from pure substances? |
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Definition
A compound always contains two or more elements joined in a fixed proportion.
The properties of a mixture can vary because the composition of a mixture is not fixed. |
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Term
| What is the main difference among solutions, suspensions, and colloids? |
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Definition
| Based on the size of its largest particles, a mixture can be classfied as a solution, a suspension, or a colloid. |
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Term
| What are some examples of physical properties? |
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Definition
| Viscosity, conductivity, malleability, hardness, melting point, boiling point, and density are examples of physical properties. |
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Term
| How can knowing the physical properties of matter be useful? |
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Definition
| Physical properties are used to identify a material, to choose a material for a specific purpose, or to separate the substances in a mixture. |
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Term
| What processes are used to separate mixtures? |
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Definition
| Filtration and distillation are two common separation methods. |
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Term
| When does a physical change occur? |
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Definition
| A physical change occurs when some of the properties of a material change, but the substances in the material remains the same. |
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Term
| When can chemical properties be observed? |
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Definition
| Chemical properties can be observed only when the substances in a sample of matter are changing into different substances. |
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Term
| What observations might indicate that a chemical change has occurred? |
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Definition
| Three common types of evidence for a chemical change are a change in color, the production of a gas, and the formation of a precipitate. |
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Term
| What is the difference between chemical and physical change? |
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Definition
| When matter undergoes a chemical change, the composition of the matter changes. When matter undergoes a physical change, the composition of the matter remains the same. |
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Term
| How can shape and volume be used to classify materials? |
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Definition
| Materials can be classified as solids, liquids, or gases based on whether their shapes and volumes are definite or variable. |
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Term
| How can kinetic theory and forces of attraction be used to explain the behavior of gases, liquids, and solids? |
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Definition
The kinetic theory of matter says that all particles of matter are in constant motion.
There are forces of attraction among the particles in all matter.
The constant motion of particles in a gas allows a gas to fill a container of any shape or size.
A liquid takes the shape of its container because particles in a liquid can flow to new locations. The volume of a liquid is constant because forces of attraction keep particles close together.
Solids have a definite volume and shape because particles in a solid vibrate around fixed locations. |
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Term
| What causes gas pressure in a closed container? |
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Definition
| Collisions between particles of a gas and the walls of the container cause the pressure in a closed container of gas. |
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Term
| What factors affect gas pressure? |
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Definition
Factors that affect the pressure of an enclosed gas are its temperature, its volume, and the number of its particles.
Raising the temperature of a gas will increase its pressure if the volume of the gas and the number of particles are constant.
Reducing the volume of a gas increases its pressure if the temperature of the number of particles are constant.
Increasing the number of particles will increase the pressure of a gas if the temperature and the volume are constant. |
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Term
| How are the temperature, volume, and pressure of a gas related? |
|
Definition
Charles's Law
V1/T1=V2/T2
Boyle's Law
P1V1=P2V2
Combined Gas Law
P1V1/T1=P2V2/T2 |
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Term
| What are six common phase changes? |
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Definition
| Melting, freezing, vaporization, condensation, sublimation, and deposition are six common phase changes. |
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Term
| What happens to a substance's temperature and a system's energy during a phase change? |
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Definition
The temperature of a substance does not change during a phase change.
Energy is either absorbed or released during a phase change. |
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Term
| How does the arrangement of water molecules change during melting and freezing? |
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Definition
| The arrangement of molecules in water become less orderly as water melts and more orderly as water freezes. |
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Term
| How are evaporation and boiling different? |
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Definition
| Evaporation takes place at the surface of a liquid and occurs at temperatures below the boiling point. |
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Term
| What was Dalton's theory of the structure of matter? |
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Definition
| Dalton proposed the theory that all matter is made up of individual particles called atoms, which cannot be divided. |
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Term
| What contributions did Thomson and Rutherford make to the development of atomic theory? |
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Definition
Thomson's experiments provided the first evidence that atoms are made of even smaller particles.
According to Rutherford's model, all of an atom's positive charge is concentrated in its nucleus. |
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Term
| What are three subatomic particles? |
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Definition
| Protons, electrons, and neutrons are subatomic particles. |
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Term
| What properties can be used to compare protons, electrons, and neutrons? |
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Definition
| Protons, electrons, and neutrons can be distinguished by mass, charge, and location in an atom. |
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Term
| How are atoms of one element different from atoms of other elements? |
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Definition
| Atoms of different elements have different numbers of protons. |
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Term
| What is the difference between two isotopes of the same element? |
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Definition
| Isotopes of an element have the same atomic number but different mass numbers because they have different numbers of neutrons. |
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Term
| What can happen to electrons when atoms gain or lose energy? |
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Definition
| An electron in an atom can move from one energy level to another when the atom gains or looses energy. |
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Term
| What model do scientists use to describe how electrons behave in atoms? |
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Definition
Scientists use the electron cloud model to describe the possible locations of electrons around the nucleus.
An electron cloud is a good approximation of how electrons behave in their orbitals. |
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Term
| What is the most stable configuration of electrons in an atom? |
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Definition
| The most stable electron configuration is the one in which the electrons are in orbitals with the lowest possible energies. |
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Term
| How did Mendeleev organize the elements in his periodic table? |
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Definition
| Mendeleev arranged the elements into rows in order of increasing mass number so that elements with similar properties were in the same column. |
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Term
| What evidence helped verify the usefulness of Mendeleev's table? |
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Definition
| The close match between Mendeleev's predictions and the actual properties of new elements showed how useful his periodic table could be. |
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Term
| How is the modern periodic table arranged? |
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Definition
In the modern periodic table, elements are arranged by increasing atomic number (number of protons).
Properties of elements repeat in a predictable way when atomic numbers are used to arrange elements into groups. |
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Term
| What does the atomic mass of an element depend on? |
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Definition
| Atomic mass is a value that depends on the distribution of an element's isotopes in nature and the masses of those isotopes. |
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|
Term
| What categories are used to classify elements on the periodic table? |
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Definition
| Elements are classified as metals, nonmetals, and metalloids. |
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Term
| How do properties vary across a period in the periodic table? |
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Definition
| Across a period from left to right, elements become less metallic and more nonmetallic in their properties. |
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|
Term
| Why do elements in a group have similar properties? |
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Definition
| Elements in a group have similar properties because they have the same number of valence electrons. |
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Term
| What are some properties of the A groups in the periodic table? |
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Definition
The reactivity of alkali metals increases from the top of Group 1A to the bottom.
Differences in reactivity among the alkaline earth metals are shown by the ways they react with water.
Aluminum is the most abundant metal in Earth's crust.
Except for water, most of the compounds in your body contain carbon.
Besides nitrogen, fertilizers often contain phosphorus.
Oxygen is the most abundant element in Earth's crust.
Despite their physical differences, the halogens have similar chemical properties.
The noble gases are colorless and odorless and extremely nonreactive. |
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Term
| When is an atom unlikely to react? |
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Definition
| When the highest occupied energy level of an atom is filled with electrons, the atom is stable and not likely to react. |
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Term
| What is one way in which elements can achieve stable electron configurations? |
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Definition
| Some elements achieve stable electron configurations through the transfer of electrons between atoms. |
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|
Term
| How does the structure of an ionic compound affect its properties? |
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Definition
| The properties of an ionic compound can be explained by the strong attractions among ions within a crystal lattice. |
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|
Term
| How are atoms held together in a covalent bond? |
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Definition
| The attractions between the shared electrons and the protons in each nucleus hold the atoms together in a covalent bond. |
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Term
| What happens when atoms don't share electrons equally? |
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Definition
| When atoms form a polar covalent bond, the atom with the greater attraction for electrons has a partial negative charge. The other atom has a partial positive charge. |
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|
Term
| What factors determine whether a molecule is polar? |
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Definition
| The type of atoms in a molecule and its shape are factors that determine whether a molecule is polar or nonpolar. |
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|
Term
| How do attractions between polar molecules compare to attractions between nonpolar molecules? |
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Definition
| Attractions between polar molecules are stronger that attractions between nonpolar molecules. |
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Term
| What information do the name and formula of an ionic compound provide? |
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Definition
| The name of an ionic compound must distinguish the compound from other ionic compounds containing the same elements. The formula of an ionic compound describes the ratio of the ions in the compound. |
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Term
| What information do the name and formula of a molecular compound provide? |
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Definition
| The name and formula of a molecular compound describe the type and number of atoms in a molecule of the compound. |
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Term
| What are the forces that give a metal its structure as a solid? |
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Definition
| the cations in a metal form a lattice that is held in place by strong metallic bonds between the cations and the surrounding valence electrons. |
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|
Term
| How do metallic bonds produce some of the typical properties of metals? |
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Definition
| The mobility of electrons within a metal lattice explains some of the properties of metals. |
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|
Term
| How are the properties of alloys controlled? |
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Definition
| Scientists can design alloys with specific properties by varying the types and amounts of elements in an alloy. |
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|
Term
| What is the Law of Conservation of Mass? |
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Definition
| The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction. |
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|
Term
| Why must chemical equations be balanced? |
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Definition
| In order to show that mass is conserved during a reaction, a chemical equation must be balanced. |
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|
Term
| Why do chemists use the mole? |
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Definition
| Because chemical reactions often involve large numbers of particles, chemists use a counting unit called a mole to measure amounts of a substance. |
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Term
| How can you calculate the mass of a reactant or product in a chemical reaction? |
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Definition
| In chemical reactions, the mass of a reactant of product can be calculated by using a balanced chemical equation and molar masses of the reactants and products. |
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|
Term
| What are the general types of chemical reactions? |
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Definition
| Some general types of chemical reactions are synthesis reactions, decomposition reactions, single-replacement reactions, double-replacement reactions, and combustion reactions. |
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Term
| How did the discovery of subatomic particles affect the classification of reactions? |
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Definition
| The discovery of subatomic particles enabled scientists to classify certain chemical reactions as transfers of electrons between atoms. |
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|
Term
| What happens to chemical bonds during a chemical reaction? |
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Definition
| Chemical reactions involve the breaking of chemical bonds in the reactants and the forming of chemical bonds in the products. |
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|
Term
| What happens to energy during a chemical reaction? |
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Definition
| During a chemical reaction, energy is neither released nor absorbed. |
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|
Term
| What does a reaction rate tell you? |
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Definition
| Reaction rates tell you how fast a reaction is going. |
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|
Term
| What factors cause reaction rates to change? |
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Definition
| Factors that affect reaction rates include temperature, surface area, concentration, stirring, and catalysts. |
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|
Term
| Under what conditions do physical and chemical equilibria occur? |
|
Definition
When a physical change does not go to completion, a physical equilibrium is established between the forward and reverse changes.
When a chemical reaction does not go to completion, a chemical equilibrium is established between the forward and reverse reactions. |
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|
Term
| How do equilibrium systems respond to change? |
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Definition
| When a change is introduced to a system in equilibrium, the equilibrium shifts in the direction that relieves the change. |
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|
Term
| What are three processes that can occur when substances dissolve? |
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Definition
| Substances can dissolve in three ways - by dissociation, dispersion, and ionization. |
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Term
| What are some properties of a solution that differ form those of its solvent and solutes? |
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Definition
| Three physical properties of a solution that can differ from those of its solute and solvent are conductivity, freezing point, and boiling point. |
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|
Term
| What happens to energy when a solution forms? |
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Definition
| During the formation of a solution, energy is either released or absorbed. |
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|
Term
| What factors affect the rate of dissolving? |
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Definition
| Factors that affect the rate of dissolving include surface area, stirring, and temperature. |
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|
Term
| How are solutions with different amounts of solute described? |
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Definition
| Solutions are described as saturated, unsaturated, or supersaturated, depending on the amount of solute in solution. |
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|
Term
| What factors determine the solubility of a solute? |
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Definition
| Three factors that affect the solubility of a solute are the polarity of the solvent, temperature, and pressure. |
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|
Term
| What are three ways to measure the concentration of a solution? |
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Definition
| Concentration can be expressed as percent by volume, percent by mass, and molarity. |
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|
Term
| What are some general properties of acids and bases? |
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Definition
Some general properties of acids include sour taste, reactivity with metals, and ability to produce color changes in indicators.
Some general properties of bases include bitter taste, slippery feel, and the ability to produce color changes in indicators. |
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|
Term
| What are the products of neutralization? |
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Definition
| The neutralization reaction between an acid and a base produces a salt and water. |
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|
Term
| What are proton donors and proton acceptors? |
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Definition
| Acids can be defined as proton donors, and bases can be defined as proton acceptors. |
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|
Term
| How is pH used to describe the concentration of acids and bases? |
|
Definition
The lower the pH value, the greater the H3O+ ion concentration in the solution is.
The higher the pH value, the lower the H3O+ ion concentration in the solution is. |
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|
Term
| How do strong acids and bases differ from weak acids and bases? |
|
Definition
When strong acids dissolve in water, they ionize almost completely.
Strong bases dissociate almost completely in water.
Weak acids and bases ionize or dissociate only slightly in water. |
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|
Term
| Why are strong acids and bases good electrolytes? |
|
Definition
| Strong acids and bases are strong electrolytes because they dissociate or ionize almost completely in water. |
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|
Term
| What are three forms of carbon? |
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Definition
| Diamond, graphite, and fullerenes are forms of carbon. |
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|
Term
| What factors determine the properties of a hydrocarbon? |
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Definition
| Factors that determine the properties of a hydrocarbon are the number of carbon atoms and how the atoms are arranged. |
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|
Term
| What are the three types of unsaturated hydrocarbons? |
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Definition
| There are three types of unsaturated hydrocarbons - alkenes, alkynes, and aromatic hydrocarbons. |
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|
Term
| What are the three main fossil fuels and the two primary products of their combustion? |
|
Definition
Three types of fossil fuels are coal, natural gas, and petroleum.
The primary products of the combustion of fossil fuels are carbon dioxide and water. |
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|
Term
| What functional groups are found in alcohols, organic acids, and organic bases? |
|
Definition
The functional group in an alcohol is a hydroxyl group, -OH.
The functional group in organic acids is a caboxyl group, -COOH.
The functional group in an amine is an amino group, -NH2. |
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|
Term
|
Definition
| Esters form when organic acids react with alcohols. |
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|
Term
| What is one way that polymers can be classified? |
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Definition
| Polymers can be classified as natural polymers or synthetic polymers. |
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|
Term
| What are three examples of synthetic polymers? |
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Definition
| Rubber, nylon, and polyethylene are three examples of compounds that can be synthesized. |
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|
Term
| What are the four types of polymers that organisms can produce? |
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Definition
| Four types of polymers produced in plant and animal cells are starches, cellulose, nucleic acids, and proteins. |
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|
Term
| What energy conversion takes place during photosynthesis? |
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Definition
| During photosynthesis, energy from sunlight is converted into chemical energy. |
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|
Term
| How are photosynthesis and cellular respiration related? |
|
Definition
| During cellular respiration, the energy stored in the products of photosynthesis is released. |
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|
Term
| What molecules help cells function efficiently? |
|
Definition
| Enzymes and vitamins are compounds that help cells function efficiently at normal body temperature. |
|
|
Term
| What happens during nuclear decay? |
|
Definition
| During nuclear decay, atoms of one element can change into atoms of a different element altogether. |
|
|
Term
| What are three types of nuclear radiation? |
|
Definition
| Common types of nuclear radiation include alpha particles, beta particles, and gamma rays. |
|
|
Term
| How does nuclear radiation affect atoms? |
|
Definition
| Nuclear radiation can ionize atoms. |
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|
Term
| What devices can detect nuclear radiation? |
|
Definition
| Devices that are used to detect nuclear radiation include Geiger counters and film badges. |
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|
Term
| How do nuclear decay rates differ from chemical reaction rates? |
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Definition
| Unlike chemical reaction rates, which vary with the conditions of a reaction, nuclear decay rates are constant. |
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|
Term
| How do scientists determine the age of an object that contains carbon-14? |
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Definition
| In radiocarbon dating, the age of an object is determined by comparing the object's carbon-14 levels with carbon-14 levels in the atmosphere. |
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|
Term
| How do artificial transmutations occur? |
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Definition
| Scientists can perform artificial transmutations by bombarding atomic nuclei with high-energy particles such as protons, neutrons, or alpha particles. |
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|
Term
| How are transuranium elements produced? |
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Definition
| Scientists can synthesize a transuranium element by the artificial transmutation of a lighter element. |
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|
Term
| Under what conditions does the strong nuclear force overcome electric forces in the nucleus? |
|
Definition
| Over very short distances, the strong nuclear force is much greater than the electric forces among protons. |
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|
Term
| What property of fission makes it so useful? |
|
Definition
| In nuclear fission, tremendous amounts of energy can be produced from very small amounts of mass. |
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|
Term
| What is needed to describe motion completely? |
|
Definition
| To describe motion accurately and completely, a frame of reference is necessary. |
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|
Term
| How are distance and displacement different? |
|
Definition
| Distance is the length of the path between two points. Displacement is the direction form the starting point and the length of a straight line form the starting point to the ending point. |
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|
Term
| How do you add displacements? |
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Definition
| Add displacements using vector addition. |
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|
Term
| How are instantaneous speed and average speed different? |
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Definition
| Average speed is computed for the entire duration of a trip, and instantaneous speed is measured at a particular instant. |
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|
Term
| How can you find the speed from a distance-time graph? |
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Definition
| The slope of a line on a distance-time graph is speed. |
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|
Term
| How are speed and velocity different? |
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Definition
| Velocity is a description of both speed and direction of motion. Velocity is a vector. |
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|
Term
|
Definition
| Two or more velocities add by vector addition. |
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|
Term
| How are changes in velocity described? |
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Definition
| Acceleration can be described as changes in speed, changes in direction, or changes in both. Acceleration is a vector. |
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|
Term
| How can you calculate acceleration? |
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Definition
| You calculate acceleration for straihgt-line motion by dividing the change in velocity by the total time. |
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|
Term
| How does a speed-time graph indicate acceleration? |
|
Definition
| The slope of a speed-time graph is acceleration. |
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|
Term
| What is instantaneous accleration? |
|
Definition
| Instantaneous acceleration is how fast a velocity is changing at a specific instant. |
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|
Term
| How do forces affect the motion of an object? |
|
Definition
A force can cause a resting object to move, or it can accelerate a moving object by changing the object's direction or speed.
When the forces on an object are balanced, the net force is zero and there is no change in the object's motion.
When an unbalanced force acts on an object, the object accelerates. |
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|
Term
| What are the four main types of friction? |
|
Definition
| There are four main types of friction: static friction, sliding friction, rolling friction, and fluid friction. |
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|
Term
| How do graivty and air resistance affect a falling object? |
|
Definition
| Gravity causes objects to accelerate downward, whereas air resistance acts in the direction opposite to the motion and reduces acceleration. |
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|
Term
| In what direction does Earth's gravity act? |
|
Definition
| Earth's gravity acts downward toward the center of Earth. |
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|
Term
| Why does a projectile follow a curved path? |
|
Definition
| The combination of an initial forward velocity and the downward vertical force of gravity causes the object to follow a curved path. |
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|
Term
| How does Newton's first law relate change in motion to a zero net force? |
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Definition
| According to Newton's first law of motion, that state of motion of an object does not change as long as the net force acting on the object is zero. |
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|
Term
| How does Newton's second law relate force, mass, and acceleration? |
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Definition
| According to Newton's second law of motion, the acceleration of an object is equal to the net force acting on it divided by the object's mass. |
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|
Term
| How are weight and mass related? |
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Definition
| Mass is a measure of the inertia of an object; weight is a measure of the force of gravity acting on an object. |
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|
Term
| What is Newton's third law of motion? |
|
Definition
| According to Newton's third law of motion, whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object. |
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|
Term
| What is needed for an object to have a large momentum? |
|
Definition
| An object has a large momentum if the product of its mass and velocity is large. |
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|
Term
| How is momentum conserved? |
|
Definition
| In a closed system, the loss of moentum of one object equals the gain in momentum of another object - momentum is conserved. |
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|
Term
| What force can attract and repel? |
|
Definition
| Electric force and magnetic force are the only forces that can both attract and repel. |
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|
Term
| What force holds the nucleus together? |
|
Definition
| Two forces, the strong nuclear force and the weak nuclear force, act within the nucleus to hold it together. |
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|
Term
| What is Newton's law of universal graviation? |
|
Definition
| Newton's law of universal gravitation states that every object in the universe attracts every other object. |
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|
Term
| How is pressure calculated? |
|
Definition
| To calculate pressure, divide the force by the area over which the force acts. |
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|
Term
| How does water pressure change with depth? |
|
Definition
| Water pressure increases as depth increases. |
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|
Term
| How is pressure distributed at a given level in a fluid? |
|
Definition
| The pressure in a fluid at any given depth is constant, and it is exerted equally in all directions. |
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|
Term
| How does air pressure change with altitude? |
|
Definition
| Air pressure decreases as the altitude increases. |
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|
Term
| How does Pascal's principle describe the transmission of pressure through fluid? |
|
Definition
| According to Pascal's principle, a change in pressure at any point in a fluid is transmitted equally and unchanged in all directions throughout the fluid. |
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|
Term
| How does a hydraulic system work? |
|
Definition
| In a hydraulic lift system, in increased output force is produced because a constant fluid pressure is exerted on the larger area of the output piston. |
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|
Term
| How is the speed of a fluid related to the pressure within the fluid? |
|
Definition
| According to Bernoulli's principle, as the speed of a fluid increases, the pressure within the fluid decreases. |
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|
Term
| What is the effect of buoyancy on the apparent weight of an object? |
|
Definition
| Buoyancy results in the apparent loss of weight of an object in a fluid. |
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|
Term
| How can you determine if an object will float or sink in a fluid? |
|
Definition
If an object is less dense than the fluid it is in, it will float. I the object is more dense than the fluid it is in, it will sink.
When buoyant force is equal to the weight, an object floats or is suspended. When the buoyant force is less than the weight, the object sinks. |
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|
Term
| When does a force do work? |
|
Definition
For a force to do work on an object, some of the force must act in the same direction as the object moves. If there is no movement, no work is done.
Any part of a force that does not act in the direction of motion does no work on an object. |
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|
Term
| How are work and power related? |
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Definition
| Doing work at a faster rate requires more power. To increase power, you can increase the amount of work done in a given time, or you can do a given amount of work in less time. |
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Term
| How do machines make work easier? |
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Definition
| Machines make work easier to do. They change the size of the force needed, the direction of a force, or the distance over which a force acts. |
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Term
| How are work input and work output related for a machine? |
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Definition
| Because of friction, work done by a machine is always less than the work done on the machine. |
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Term
| How does the actual mechanical advantage of a machine compare to its ideal mechanical advantage? |
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Definition
| Because friction is always present, the actual mechanical advantage of a machine is always less than the ideal mechanical advantage. |
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Term
| Why is the efficiency of a machine always less than 100 percent? |
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Definition
| Because there is always some friction, the efficiency of any machine is always less than 100 percent. |
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Term
| What are the six types of simple machines? |
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Definition
| The six types of simple machines are the lever, the wheel and axle, the inclined palne, the wedge, the screw, and the pulley. |
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Term
| What determines the mechanical advantage of the six types of simple machines? |
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Definition
To calculate the IMA of any lever, divide the input arm by the output arm.
To calculate the IMA of the wheel and axle, divide the radius (or diameter) where the input force is exerted by the radius (or diameter) where the output force is exerted.
The IMA of an inclined plane is the distance along the inclined plane divided by its change in height.
A thin wedge of a given length has a greater IMA than a thick wedge of the same length.
Screws with threads that are closer together have a greater IMA.
The IMA of a pulley or pulley system i equal to the number of rope section supporting the load being lifted. |
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Term
| How are energy and work related? |
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Definition
| Work is a transfer of energy. |
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Term
| What factors does the kinetic energy of an object depend upon? |
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Definition
| The kinetic energy of any moving object depends upon its mass and speed. |
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Term
| How is gravitational potential energy determined? |
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Definition
| An object's gravitational potential energy depends on its mass, its height, and the acceleration due to gravity. |
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Term
| What are the major forms of energy? |
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Definition
| The major forms of energy are mechanical energy, thermal energy, chemical energy, electrical energy, electromagnetic energy, and nuclear energy. |
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Term
| Can energy be converted from one form to another? |
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Definition
| Energy can be converted from one form to another. |
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Term
| What is the Law of Conservation of Energy? |
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Definition
| The Law of Conservation of Energy states that energy cannot be created or destroyed. |
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Term
| What energy conversion takes place as an object falls toward Earth? |
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Definition
| The gravitational potential energy of an object is converted to the kinetic energy of motion as the object falls. |
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Term
| How are energy and mass related? |
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Definition
| Einstein's equation, E=mc2, says that energy and mass are equivalent and can be converted into each other. |
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Term
| What are the major nonrenewable and renewable sources of energy? |
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Definition
Nonrenewable energy resources include oil, natural gas, coal, and uranium.
Renewable energy resources include hydroelectric, solar, geothermal, wind, biomass, and, possibly in the future, nuclear fission. |
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Term
| How can energy resources be conserved? |
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Definition
| Energy resources can be conserved by reducing energy needs and by by increasing the efficiency of energy use. |
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Term
| In what direction does heat flow spontaneously? |
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Definition
| Heat flows spontaneously from hot objects to cold objects? |
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Term
| What is the temperature of an object related to? |
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Definition
| Temperature is related to the average kinetic energy of the particles in an object due to their random motions through space. |
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Term
| What to variables is thermal energy related to? |
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Definition
| Thermal energy depends on the mass, temperature, and phase (solid, liquid, or gas) of an object. |
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Term
| What causes thermal expansion? |
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Definition
| Thermal expansion occurs because particles of matter tend to move farther apart as temperature increases. |
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Term
| How is change in temperature related to specific heat? |
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Definition
| The lower a material's specific heat, the more its temperature increases when heat is absorbed. |
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Term
| On what principle does a calorimeter operate? |
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Definition
| A calorimeter uses the principle that heat flows from a hotter object to a colder object until both reach the same temperature. |
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Term
| Why is conduction slower is gases than in liquids or solids? |
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Definition
| Conduction in gases is slower than in liquids and solids because the particles in a gas collide less often. |
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Term
| In what natural cycles do convection currents occur? |
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Definition
| Convection currents are important in many natural cycles, such as ocean currents, weather systems, and movements of hot rock in Earth's interior. |
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Term
| How does an object's temperature affect radiation? |
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Definition
| All object's radiate energy. As an object's temperature increases, the rate at which it radiates energy increases. |
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Term
| What are the three Laws of Thermodynamics? |
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Definition
The first law of thermodynamics states that energy is conserved.
The second law of thermodynamics states that thermal energy can flow from colder objects to hotter objects only if work is done on the system.
The third law of thermodynamics state that absolute zero cannot be reached. |
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Term
| What are the two main types of heat engines? |
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Definition
| The two main types of heat engines are the external combustion engine and the internal combustion engine. |
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Term
| How do most heating systems distribute thermal energy? |
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Definition
| Most heating systems use convection to distribute thermal energy. |
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Term
| How does a heat pump reverse the normal flow of heat? |
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Definition
| Heat pumps must do work of a refrigerant in order to reverse the normal flow of thermal energy. |
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Term
| What causes mechanical waves? |
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Definition
| A mechanical wave is created when a source of energy causes vibration to travel through a medium. |
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Term
| What are the three main types of mechanical waves? |
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Definition
| The three main types of mechanical waves are transverse waves, longitudinal waves, and surface waves. |
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Term
| What determines the frequency of a wave? |
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Definition
| A wave's frequency equals the frequency of the vibrating source producing the wave. |
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Term
| How are frequency, wavelength, and speed related? |
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Definition
Increasing the frequency of a wave decreases its wavelength.
If you assume that waves are traveling at a constant speed, then wavelength is inversely proportional to frequency. |
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Term
| How is the amplitude of a wave related to the wave's energy? |
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Definition
| The more energy a wave has, the greater is its amplitude. |
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Term
| How does reflection change a wave? |
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Definition
| Reflection does not change the speed or frequency of a wave, but the wave can be flipped upside down. |
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Term
| What causes the refraction of a wave when it enters a new medium? |
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Definition
| When a wave enters a medium at an angle, refraction occurs because one side of the wave moves more slowly than the other side. |
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Term
| What factors affect the amount of diffraction of a wave? |
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Definition
| A wave diffracts more if its wavelength is large compared to the size of the opening or obstacle. |
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Term
| What are two types of interference? |
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Definition
| Two types of interference are constructive interference and destructive interference. |
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Term
| What wavelengths will produce a standing wave? |
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Definition
| A standing wave forms only if half a wavelength or a multiple of half a wavelength fits exactly into the length of a vibrating cord. |
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Term
| What properties explain the behavior of sound? |
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Definition
| Many behaviors of sound can be explained by using a few properties - speed, intensity and loudness, and frequency and pitch. |
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Term
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Definition
| Ultrasound is used in a variety of applications, including sonar and ultrasound imaging. |
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Term
| How does frequency of sound change for a moving source? |
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Definition
| As a source of sound approaches, an observer hears a higher frequency. When the sound source moves away, the observer hears a lower frequency. |
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Term
| What are the functions of the three main regions of the ear? |
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Definition
| The outer ear gathers and focuses sound into the middle ear, which receives and amplifies the vibrations. The inner ear uses nerve endings to sense vibrations and send signals to the brain. |
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Term
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Definition
| Sound is recorded by converting sound waves into electronic signals that can be processed and stored. Sound is reproduced by converting electronic signals back into sound waves. |
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Term
| How do musical instruments vary pitch? |
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Definition
| Most musical instruments vary pitch by changing the frequency of standing waves. |
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Term
| How are electromagnetic waves different from mechanical waves? |
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Definition
Electromagnetic waves are produced when an electric charge vibrates or accelerates.
Electromagnetic waves can travel through a vacuum, or empty space, as well as through matter. |
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Term
| What is the maximum speed of light? |
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Definition
| The speed of light in a vacuum, c, is 3.00x10^8 meters per second. |
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Term
| How do electromagnetic waves differ from one another? |
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Definition
| Electromagnetic waves vary in wavelength and frequency. |
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Term
| What is the dual nature of electromagnetic radiation? |
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Definition
| Electromagnetic radiation behaves sometimes like a wave and sometimes like a stream of particles. |
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Term
| What happens as light travels farther from its source? |
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Definition
| The intensity of light decreases as photons travel farther from the source. |
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Term
| What waves are included in the electromagnetic spectrum? |
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Definition
| The electromagnetic spectrum includes radio waves, infrared rays, visible light, ultraviolet rays, X-rays, and gamma rays. |
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Term
| How is each type of electromagnetic wave used? |
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Definition
Radio waves are used in radio and television technologies, as well as in microwave ovens and radar.
Infrared rays are used as a source of heat and to discover areas of heat differences.
People use visible light to see, to help keep them safe, and to communicate with one another.
Ultraviolet rays have applications in health and medicine, and in agriculture.
X-rays are used in medicine, industry, and transportation to make pictures of the inside of solid objects.
Gamma rays are used in the medical field to kill cancer cells and make pictures of the brain, and in industrial situations as an inspections. |
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Term
| What three types of materials affect the behavior of light? |
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Definition
| Materials can be transparent, translucent, or opaque. |
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Term
| How does light behave when it enters a new medium? |
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Definition
| When light strikes a new medium, the light can be reflected, absorbed, or transmitted. When light is transmitted, it can be refracted, polarized, or scattered. |
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Term
| How does a prism separate white light? |
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Definition
| As white light passes through a prism, shorter wavelengths refract more than longer wavelengths, and the colors separate. |
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Term
| What determines the color of an object? |
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Definition
| The color of any object depends on what the object is made of and on the color of light that strikes the object. |
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Term
| What are the primary colors of light? |
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Definition
| The primary colors of light are red, green, and blue. |
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Term
| What are the primary colors of pigment? |
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Definition
| The primary colors of pigment are cyan, yellow, and magenta. |
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Term
| What are the six common sources of light? |
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Definition
| Common sources of light include incandescent, fluorescent, laser, neon, tungsten-halogen, and sodium-vapor bulbs. |
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Term
| How does each type of light source generate light? |
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Definition
When electrons flow through the filament of an incandescent bulb, the filament gets hot and emits light.
Fluorescent light bulbs emit light by causing a phosphor to steadily emit photons.
Laser light is emitted when excited atoms of a solid, liquid, or gas emit photons.
Neon lights emit light when electrons move through a gas or a mixture of gases inside glass tubing.
As electric current passes through a sodium-vapor bulb, it ionizes the gas mixture. The mixture warms up and the heat causes the sodium to change from a solid into a gas.
Inside a tungsten-halogen bulb, electrons flow through a tungsten filament. The filament gets hot and emits light. |
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Term
| What produces a net electric charge? |
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Definition
| An excess or shortage of electrons produces a net electric charge. |
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Term
| What determines whether an electric force is attractive or repulsive? |
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Definition
| Like charges repel, and opposite charges attract. |
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Term
| What determines the strength of an electric field? |
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Definition
| The strength of an electric field depends on the amount of charge that produces the field and on the distance from the charge. |
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Term
| What are three ways in which charge is transferred? |
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Definition
| Charge can be transferred by friction, by contact, and by induction. |
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Term
| How does a static discharge occur? |
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Definition
| Static discharge occurs when a pathway through which charges can move forms suddenly. |
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Term
| What are the two types of current? |
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Definition
| The two types of current are direct current (DC) and alternating current (AC). |
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Term
| What are some examples of conductors and insulators? |
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Definition
| Metals such as copper and silver are good electrical conductors. Wood, plastic, rubber, and air are good electrical insulators. |
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Term
| What factors affect electrical resistance? |
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Definition
| A material's thickness, length, and temperature affect its resistance. |
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Term
| What causes an electric current? |
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Definition
| In order for charge to flow in a conducting wire, the wire must be connected in a complete loop that includes a source of electrical energy. |
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Term
| How are voltage, current, and resistance related? |
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Definition
| Increasing the voltage increase the current. Keeping the same voltage and increasing resistance decreases the current. |
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Term
| What is included in a circuit diagram? |
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Definition
| Circuit diagrams use symbols to represent parts of a circuit, including a source of electrical energy and devices that are run by the electrical energy. |
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Term
| How do series and parallel circuits differ? |
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Definition
If on element stops functioning in a series circuit, none of the elements can operate.
If one element stops functioning in a parallel circuit, the rest of the elements still can operate. |
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Term
| How do you calculate electric power and electrical energy use? |
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Definition
Electric power can be calculated by multiplying voltage and current.
Electrical energy use can be calculated by multiplying power by time. |
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Term
| What devices make electricity safe to use? |
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Definition
| Correct wiring, fuses, circuit breakers, insulation, and grounded plugs help make electrical energy safe to use. |
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Term
| How do electronic signals convey information? |
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Definition
| Electronics conveys information with electrical patterns called analog and digital signals. |
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Term
| How do vacuum tubes control electron flow? |
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Definition
| Vacuum tubes can change alternating current in direct current, increase the strength of a signal, or turn a current on or off. |
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Term
| What are two types of semiconductors? |
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Definition
| In n-type semiconductors, the current is a flow of electrons. In p-type semiconductors, it appears as though positive charge flows. |
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Term
| How are semiconductors used? |
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Definition
| Most modern electronic devices are controlled by solid-state components. |
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Term
| What are the benefits of using microchips in communication devices? |
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Definition
| Communication devices use microchips to make them more portable, reliable, and affordable. |
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Term
| How do magnetic poles interact? |
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Definition
| Like magnetic poles repel on another, and opposite magnetic poles attract one another. |
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Term
| How can a magnetic field affect a magnet that enters the field? |
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Definition
| A magnetic field, which is strongest near the magnet's poles, will either attract or repel another magnet that enters the field. |
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Term
| Why are some materials magnetic while others are not? |
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Definition
| When a material is magnetized, most of its magnetic domains are aligned. |
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Term
| How can an electric charge create a magnetic field? |
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Definition
| Moving electric charges create a magnetic field. |
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Term
| How is an electromagnet controlled? |
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Definition
| Changing the current in an electromagnet controls the strength and direction of its magnetic field. |
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Term
| How do galvanometers, electric motors, and loudspeakers work? |
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Definition
| Electromagnetic devices such as galvanometers, electric motors, and loudspeakers change electrical energy into mechanical energy. |
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Term
| How is voltage induced in a conductor? |
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Definition
| According to Faraday's law, a voltage is induced in a conductor by a changing magnetic field. |
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Term
| What are two types of generators? |
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Definition
| The two types of generators are AC generators and DC generators. |
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Term
| How can a transformer change voltage and current? |
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Definition
| A transformer changes voltage and current by inducing a changing magnetic field in one coil. This changing field then induces an alternating current in a nearby coil with a different number of turns. |
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Term
| What are some sources of electrical energy in the United States? |
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Definition
| Most of the electrical energy generated in the United States is produced using coal as an energy source. Some other sources are water (hydroelectric), nuclear energy, wind, natural gas, and petroleum. |
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