Term
| What is the difference between elements and compounds? |
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Definition
| Elements cannot be broken down into other substances and consist of one element. Compounds can be broken down into other substances and consist of two or more different elements. |
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Term
| Is O2 an element or a compound? Is NaCl an element or a compound? |
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Definition
| O2 is an element. NaCl is a compound. |
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Term
| What four elements make up 96% of living matter? |
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Definition
CHON.
(carbon, hydrogen, nitrogen, oxygen) |
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Term
| What are some elements that make up 4% of living matter? |
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Definition
PSCaK
Phosphorus, sulfur, calcium, potassium |
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Term
| What are trace elements and what are some examples of them? |
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Definition
| Trace elements are elements that an organism needs in very small quantities. An example of a trace element is iodine. Without it people get goiter. |
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Term
| What is the smallest unit of matter the still retains the properties of an element? |
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Definition
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Term
| What are the three main subatomic particles and what are their charges? |
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Definition
Proton- positive
Neutron- neutral
electrons- negative |
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Term
| What is found in the nucleus? What is found outside the nucleus in the cloud? |
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Definition
| Protons and neutrons are found in the nucleus. Electrons moving at nearly the speed of light form a cloud around the nucleus. |
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Term
| The mass of an electron is only _____ as much as the mass of a proton or neutron. |
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Definition
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Term
| What unit of measurement is used for atoms and subatomic particles? |
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Definition
| dalton, Atomic mass unit, amu |
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Term
[image]
What is the atomic number?
What is the mass number? |
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Definition
Atomic number-30
Mass number-65 |
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Term
[image]
How many protons, electrons, and neutrons does this element have?
(exclude the 2+) |
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Definition
Protons-30
Electrons-30
Neutrons-35 |
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Term
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Definition
| Atoms of the same element that have different amounts of neutrons. |
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Term
| What is a radioactive isotope and how are they used in science? |
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Definition
| The nucleus of a radioactive isotope decays spontaneously, giving off particles and energy. It is used in radioactive dating(C-14), monitoring biological processes, and diagnosing illness. |
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Term
Where is most of the mass of an atom?
Are atoms really mostly empty space? |
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Definition
| Most of the mass of an atom is in the nucleus. Atoms are mostly empty space. |
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Term
| Which has more potential energy: a penny on the ground or a penny on top of a building? Why? |
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Definition
| The penny on top of the building has more potential energy because of its altitude. |
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Term
| Which electrons have more potential energy: the electrons closer to the nucleus of the electrons farther away from the nucleus? |
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Definition
| The ones farther away from the nucleus. |
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Term
| How does an electron jump between energy levels? Can an electron exist(for a long time) between its energy levels? |
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Definition
| An electron can jump between energy levels by absorbing or losing energy. An electron cannot exist between its energy levels. |
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Term
| How many electrons can be in the first electron shell? The second? |
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Definition
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Term
| How many orbitals are in the first electron shell? In the second? What are the shells called? |
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Definition
First- one orbital, 1s
Second- four orbitals, 2s, 2py, 2pz, 2px |
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Term
| What is an orbital and how many electrons can be in one orbital? |
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Definition
| An orbital is a 3D space where an electron is found 90% of the time. Up to two electrons can be in each orbital. |
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Term
| What is the difference between a covalent bond and an ionic bond? |
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Definition
| In a covalent bond atoms share electrons. In an ionic bond, one atom loses electron(s)and another atom gains electron(s). |
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Term
| When two oxygen atoms share two pairs of electrons, is that a double or single bond? |
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Definition
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Term
| Covalent is to molecule as ionic is to ____? |
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Definition
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Term
| How does electronegativity affect the polarity of molecules? |
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Definition
| If two covalently bonded atoms are equally electronegative, then they have a nonpolar bond. If the atoms have different levels of electronegativity, then the molecule is polar. |
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Term
Is water a nonpolar or polar bond?
Hydrogen has low electronegativity and oxygen has a very high electronegativity. |
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Definition
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Term
| What is a positive ion called? A negative ion? |
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Definition
Positive- cation
Negative- anion |
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Term
| Can the term ion be applied to whole molecules, or only single atoms? |
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Definition
| It can be used with molecules that are electrically charged, such as ammonium. |
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Term
| How can weak bonds be an advantage in living organisms? |
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Definition
| Two molecules can come together, respond to one another in some way and separate, without the use of too much energy. |
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Term
| When does a hydrogen bond form? |
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Definition
| When a hydrogen covalently bonded to one electronegative atom is attracted to another electronegative atom. For example, water. |
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Term
| Why do Van der Waals interaction occur? |
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Definition
| They occur because electrons are always in constant motion, so one part of a molecule may be a little positive or negative. This enables molecules to stick to each other. It is also why when people pour water out of a cup, the water runs down the side of the cup instead of into the container it was suppose to go into. |
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Term
| When can Van der Waals interactions occur? |
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Definition
| When atoms and molecules are very close to each other. |
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Term
| Why is the precise shape of a molecule important? |
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Definition
| The shape of a molecule determines how it will be recognized and how it will respond with other molecules. |
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Term
| What is the angle at which the hydrogens in water are bent? |
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Definition
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Term
| In a chemical reaction, the starting materials are called_____ and the end materials are called______. |
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Definition
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Term
True or false.
Most reactions are reversible. |
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Definition
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Term
| True or false. In chemical equilibrium, the reactants and products are equal in concentration. |
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Definition
| False. The concentrations are not necessarily equal. They have only stabilized at a particular ratio. |
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Term
| What happens when chemical equilibrium is reached? |
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Definition
| The reactions offset each other. Aka, reactants and products are being made at the same rate. |
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Term
| What is the chemical equation for photosynthesis? (just for fun) |
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Definition
| 6CO2 + 6H2O ==> C6H12O6 + 6O2 |
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