Atom

-Atom is the smallest unit of an element.

-Mainly made of neutron, proton and electron.

Example:

[image]                                 

Element

-Element is a type of atom, a substance that cannot separated into simpler substance.

Example: O, H, C, Cu, Fe, etc.

 Molecule

-A group of atoms combine together.

ex) H₂O, CO₂:

[image]

 Compound

-Compound is a pure substance bonded together by molecule.

ex) Ice____lots of water(H₂O) molecule bonded together and frozen.

 Subatomic particle

-Smaller particle that formed nuclei and atoms.

ex) Proton, neutron, electron.

-Protons and neutrons formed nuclei.

-Protons are made by 2 up quarks and a done quark.

-Neutrons are made by 2 down quarks and a up quark.

Proton(up) and Neutron(down)

[image][image]

Nucleus

-A part of atom that is densely packed protons and neutrons.

ex)

[image]

Proton

-Subatomic particle that have a positive charge.

ex.) Lithium(Li) atom has 3 protoms, therefore the charge of nucleus is +3

Neutron

-Subatomic particle that have no charge.

ex.)Beryllium atom has 4 protons and 5 neutrons, but the charge of nucleus is only +4, therefore neutrons have no charge.

Electron

-Subatomic particle that have a negative charge.

ex) see the diagram of "atom".

-Nucleus is surrounded by electrons. An electron has a mass that's approximately 1/1836 that of the proton.

Atomic number

-Organized the "thing" elements, same as the number of protons.

-Found on the upper left corner of the periodic table.

ex) For hydrogen, the atomic number is 1 because it has one proton in each atom.

Ionic number

-Combining capacity, metals: positive; non-metal: negative.

-It's a positive or negative charge that an ion has.

ex) sodium ion has a charge of +1(metal);

     chlorine ion has a charge of -1(non-metal).

Ion

-The atom with charge(by lose or gain electrons), could be positive or negative.

ex) Sodium(see the diagram below), matal, easy to lose electrons.

[image]

When it lose the valent electron, it becomes ion.

Periodic table

-A table to show chemical elements(well organized).

ex)

[image]

Group/Family

-Row of the periodic table.

-They behave in similar ways, has the same nombers of electron on outer shell.

-Difference: as going down, each element increases by 1 shell.

 -4 different families: Alkali metals, alkali earth metals, halogens, noble gases.(can be found on PR)

ex)H, Li, Na, K, Rb, Cs, Fr are in one group(group 1).

Family

Period

-Across line of Periodic table.

ex)- elements increase by one proton

-Same numbers of shell goint across.

-see the diagram of "periodic table"

Metal

-Elements that found on left side of periodic table.

-Given electrons and ion charge is positive.

ex) Cu, Fe, Hg........

Non-metal

-Elements found on right side of PT.

-gain electrons and the ioncharge is negative

ex) C, N, O, Ne, S etc.

Atomic Mass

-Velative mass mostly protons and neutrons. 

-Below of an element pic.

ex)Carbon

[image]

the # at the bottom is the atomic mass.

Valence shell &electrons

-Valence Shell:The outer shell of an atom of bohr model.

-Valence electron: the electrons on the valence shell.

ex) Sodium(Na)

[image]

The outer shell of this model is valence shell, and there're one valence electron on the outer shell. 

Stable

-A chemical property to describe an element has a full electrons on the valent shell, don't react.

ex) Noble gases are stable.

Bohr model

-A model describes the element(atom).

-Shows all the rings, electrons including valent electrons.

ex) Aluminium(Al) bohr model

[image]

Lewis model

-A model describes the atoms.

-Only shows valence electrons

-Much easier than Bohr model.

ex)Carbon(C)

[image]

Ionic compound

-Metal and non-metal connection, gain/lose electrons.

ex) The sodium(Na) ion and chlorine(Cl) ion:

[image]

(Sodium left and chlorine right.)

Covalent compound

-Non-metal and non-metal connection.

-Sharing electrons.

ex) CH₄ (Carbon and hydrogen)

[image]

Naming

-the name of element.

[image]

ex) AlCl₃ naming: Aluminium chloride

     CO₂ naming: Carbon dioxide

Formula

-Shows how many elements does it make up, use symbol to describe.

ex) Sodium oxide: Na₂O

Unpaired electron

-The electrons aren't paired yet(single, found in valent shell)during the covalent bonding.

Long pair&Bond pair

-Long pair: electrons in the valence shell of an atom during covalent bonding.

-Bond pair: have electrons paired after compound.

ex)

[image]

Diatomic molecule

-Diatomic molecules are molecules composed only of two atoms, of either same or different atoms.

ex) 8 common: F₂, H₂, O₂, N₂, Br₂, At₂, Cl₂, I₂

Cation/Anion

-Cation: Ion with a positive charge.

-Anion: Ion with a negative charge.

ex) Cation: Metals

     Anion: Non-metals.

Equation

- An equation is a mathematical statement that asserts the equality of two expressions.

-Chemical equation is a statement that describe how chemical reacts.

ex) 2H₂+O₂→2H₂O

Physical & Chemical change

-Physical change: a change with no new bonds

-Chemical change: Make sth new.

ex) 

Physical change: Ice→water→steam

      -water frozen, ice melt...but still water.

Chemical change: 2H₂+O₂→2H₂O

Catalyst

-Catalyst is a material that can speed up the chemical reaction/increase the rate of reaction.

ex) enzyme is a catalyst, when H₂O₂ reacts, MnO₂ can be a catalyst.

pH scale

-A number scale from 1-14

-Tells if it's an acid or base

-1=strong acid, 14=strong base, 7=neutral

ex)  [image]

Indicator

-A chemical detector of protons in acid-base titration.

ex) Metyl Orange(red→yellow)

     Metyl red(red→yellow)

    Litmus(red→blue)

    Bromothymol blue(yellow→blue)

Acid

-Substance that have a pH that is less than 7.

-All contain a hydrogen atom.

ex) HCl, CH₃COOH, H₂SO_4.....

Base

-Substance that have a pH that is greater than 7.

-All base have hydroxide.

-Some bases are much stronger than others. Those that are called caustic.

ex) NaOH, Mg(OH)₂, NH₄OH......

Naming Acid

-if there's no oxygen, take beginning of both elements(usually hydro is the first element), add the ending "-ic" acid

-If there is oxygen with an -ate ending, take second word and change ending to "-ic acid".

-If there's oxygen with an -ite ending, take second word and change ending to "-ous acid"

 ex) HCl: hydrogen chloride

      HClO₄: Perchloric acid

      HClO₂: Chlorous acid

Organic compound

-An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecuel contain carbon.

 ex) C₂H₅OH

Endothermic & Exothermic reaction

-Endothermic reaction is a reaction that energy absorbed.

-Exothermic reaction is a reaction that energy released.

ex) Iron reacts with oxygen is an exothermic reaction; Mixing ammonium thiocyanate and barium hydroxide___endothermic reaction.

Law of conservation fo mass

-After the precipitation reaction, the mass of the products still equals the mass of the reactants. This demonstrates the Law of Conservation of Mass.

 ex) two reactants react in a inclosed container, the mass won't change after the reaction.

Radioactive Decay

-Radioactive decay is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles.

-The rate(how fast or slow) of radioactive dacay can be compared using a measurement called half-life(see at next card).

 Example:

[image]  

Half-Life

-The amount of TIME it takes 1/2 of the "stuff"(of a radioactive sample) to disappear(=decay)

-The shorter the half-life, the faster the decay.

Example:

If there're 100 C-14 atoms, after 5730 yrs, there're about 50 of them.(approximate)

Then 5730 yrs is the half-life of C-14

Parent isotope/

Daughter isotope

-Parent isotope: the one that decays.

-Daughter isotope: one of the decay products.

Example: 

C-14 decayed and produced N-14, therefore C-14 is the parent isotope and N-14 is daughter isotope.

[image]

Decay curve

-If we were to graph the number of percentage of remaining parent nuclei versus time, we sould always end up with a certain pattern. We call these graph DECAY CURVE.

-A graph shows the relationship between the time and the radioactive nuclei remaining, usually a curve.

Example:

[image]

Radioactivity

-Radioactivity is the spontaneous emission of energy from unstable atoms.

-Radioactivity is the ejection of particles or radiation from the nuclear

Example:

-There're several type of radiation, the radiation from the sun for instance, have radioactivity.

Electromagnetic radiation

-Electromagnetic radiation (EM radiation or EMR) is a form of energy emitted and absorbed by charged particles, which exhibits wave-like behavior as it travels through space. 

-EMR has both electric and magnetic field components.

 Example: Light is a kind of EMR

[image]

Frequency/Wavelength

-Frequency: the # of wavelength that pass a point in a sec. Measured in herz

-Wavelength: The distance from a point on one wave to the same point on the next wave. 

Example

[image]

Isotope

-Atoms(individual) of the same element(type) that have different # of neutrons in the nuclei.

-The weigh different amount.

Example

Atomic mass=# of neutrons +Atomic number(# of protons)

# of neutron=Atomic Mass-Atomic#

[image]

Graphing

best-fit

-Average line. 

-linear, curve(decay)

Scale

-use the entire sheet of paper

-same amount of spaces

-X and Y-axis can have different scales.

...Graph should have title , proper label and unit

Electrical repulsive force/Nuclear force

-The nucleus is full of positive charge which repel each other(push each other away). This force is called electrical repulsive force.(ERF)

-There 's also some force that holds it together called nuclear force(NR)

-Stable: NR>ERF

-Unstable: NR<ERF

Alpha radiation/particles/

decay

-Alpha radiation is a stream of alpha particles.

-Alpha particles are positively charged atomic particles.

-An alpha particle has the same combination of particles as a herlium nucleus.

 Example

[image]

Beta Radiation

-Beta radiation is a radiation of beta particle during bet a decay.

-Beta particle is an electron. We use the symbol ß or e in beta decay

-Beta decay (ß):

[image]

Gamma Radiation

-Gamma radiation consists of rays of high energy radiation. Has almost no mass and no charge.

-The release of gamma radiation doesn't change the atomic number or the mass number of the nucleus.

-The Gamma Ray is a high energy ray emitted from the nucleus. When a high-energy gamma ray is given off as the isotope falls from a high energy state to a low energy state.

Example:

[image]

Nuclear fission

-a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays), and releasing a very large amount of energy.

Example:

[image]

-We can use the energy it released to generate electricity, also can be used for nuclear weapon.

Critical Mass

-Smallest mass of radioactive substance possible to keep a chain reaction going.

-To fuse means to joining together.

-Therefore the nuclear fusion is when small nuclei joined together to make a large nucleus.

-Large amount of energy released.

Example:

Hydrogen fusion：

H-2+H-3→He-4+n(neutron)+Energy

-The nuclei must collide at very high speed for the fusion to occur, or the repulsive forces will push them apart(100,000,000 degree is  required)