Chemistry Regents

Anode

Site of oxidation (AnOx)

Arrhenius Acid

Substance that yields H+ or a hydronium ion in solution

Arrhenius Base

Substance that yields OH- ions in solution

Aqueous

A solid dissolved in water (ex: NaCl (aq) represents salt water)

Atomic Number

The number of protons in the nucleus

Atomic Mass

The combines mass of protons and neutrons

Average Kinetic Energy

Equivalent to temperature, an increase in temperature results in an increase in kinetic energy.

Binary Compound

A compound that contains only two elements(KCl or NaCl)

Bright Line Spectrum

Light that is produced from an electron releasing energy when it moves from a higher principal energy level to a lower principal energy level

Cathode

Site of reduction (RedCat)

Chemical Change

A change in Chemical composition

Chromatography

Separation of two or more substances in a mixture based on the solubility in water

Coefficient

Large number in front of formulas in a chemical equation (4H2O)

Combustion

Reaction between hydrocarbon and oxygen, products are Carbon Dioxide and Water

Compound

A chemical combination of two or more elements, can only be separated by chemical means

Concentrated

A large amount of solute to a small amount of solvent - ex: Concentrated iced tea is very sweet - large amount of iced tea mix to a small amount of water

Covalent Bond

Formed by a sharing of electrons

Decomposition

Breakdown of a larger molecule into smaller pieces.
Ex: 2 H2O ---> 2 H2 + O2

Diatomic Molecule

Molecules that travel in pairs (HOFBrINCl)

Dilute

A small amount of solute to a large amount of solvent - small amount of iced tea mix to a large amount of water

Distillation

The separation of two liquids by a difference in boiling temperature

Double Replacement Reaction

Reaction involving two compounds in which the metals in the reaction switch places.
Ex: 2NaCl + K2SO4 ---> Na2SO4 + 2KCl

Ductile

To be made into a wire

Element

A substance that cannot be decomposed by a physical or chemical change

Electrolyte *

A substance that when dissolved in water dissociated into ions that can conduct an electrical charge

Electronegativity

The measure of the attractive force of a nucleus for electrons, the higher the electronegativity value the easier it is for an atom to gain electrons.

What is a common electronegativity question?

"Which of the following elements will gain an electron most easily?"

Empirical Formula

A formula where the subscripts are reduced to the lowest terms possible

Endothermic

Absorbs heat

Enthalpy

Represents heat; Things in nature tend to go towards a state of lower enthalpy

Entropy

Randomness or disorder - things in nature tend to go toward a state of higher entropy

Equilibrium

The rate of the forward and reverse reaction at equilibrium is established in a closed container- the concentration of reactants and products are constant

Excited state electron configuration

Electrons gain energy and move from a lower principal energy level to a higher principal energy level, The electrons are not in the lowest energy states possible.

Exothermic

Releases heat

Filtration

Process by which an insoluble solid can be separated from a liquid

Gram Formula Mass

The mass of one mole of a substance calculated by adding up the mass of each element in the compound

Group

The numbered vertical columns on the periodic table; has similar chemical properties and bond similarly

Heat of Fusion

Heat needed to melt 1g of a substance at its melting temperature

Head of vaporization

Heat needed to boil 1g of a substance at its boiling temperature

Heterogeneous Mixture

A mixture that is not uniform, the pieces of the mixture can be seen

Homogeneous Mixture

A uniform mixture, the pieced of the mixture cannot be seen

Hydrocarbon

Organic molecule that contains only hydrogen and carbon molecules- the 4 types are Alkane, Alkene, Alkyne, and aromatics

Hydrogen bond

Type of intermolecular force formed between molecules that contain hydrogen bonded to a small atom with a large electronegativity value H is on the FON

Ideal Gas

Do not exist; real gases behave most like ideal gases when PLIGHT- pressure low, ideal gas, high temp

Immiscible

Two liquids that do not mix

Ion

An atom that has gained or lost electrons and now carries a charge

Ionic Bond

A bond that results from the transfer of electrons from one atom to another

Ionization Energy

The energy needed to remove an electron from the valence shell of an atom

Common questions about Ionization Energy

"Which of the following elements will lose an electron most easily?" (lowest IE value)

Intermolecular force

Force between molecules that holds molecules together in a solid or liquid. The higher the boiling temperature of a substance, the stronger the intermolecular force

isomer

Organic molecules that have the same molecular formula but in a different structure

Isotope

Elements that have the same number of protons but a different mass because of more or less electrons

Joule

Unit used to measure heat energy

Law of Conservation of Mass

In a chemical reaction there is no noticeable change in mass from the beginning to the end of the reaction

Malleable

To be flattened into thin sheets

Metallic Bonding

Occurs in a metal, metallic bonding results when a mobile sea of electrons surrounding positively charged nuclei

Metalloid

An element that has both properties of a metal and a nonmetal

Miscible

Two liquids that mix or are able to dissolve in one another

Mixture

Two substances physically combined, can be separated by physical means

Molarity

Term used to measure the concentration of a solution; represents the number of moles of solute dissolved in each liter of solution

Mole

Unit representing the number of atoms in a given volume

Molecular Formula

A chemical formula that has subscripts that can be reduced

Monatomic

Elements that are un-reactive or do not combine. ex: group 18

Noble Gas

Group 18 molecule that has a stable electron configuration

Nonpolar Covalent Bond

A bond made from the sharing of electrons between two of the same nonmetals

Nucleon

Subatomic particles in the nucleus- protons and neutrons

Oxidation

Loss of electrons; occurs at the anode in a voltaic and electrolytic cell

Oxidation state

The charge that an element forms when it gains or loses electrons, oxidation states for each element can be found on the periodic table

Parts Per Million

Used to express concentration of a solution made of an extremely small amount of solute

Physical change

A change that does not result in the change of composition of the material

Period

A row on the periodic table that have the same number of principal energy levels

Polar Covalent Bond

A bond that results in a sharing of electrons from two different nonmetals

Precipitate

An insoluble product formed in a double replacement reaction -- table F

Reduction

Gain of electrons; occurs in the cathode

Salt

Any ionic compound

Salt Bridge

Permits the migration of ions in order to keep solutions in a voltaic cell electrically neutral

Saturated Solution

Solution that holds as much solute as allowed by its solubility at a given temperature

Single Replacement Reaction

Reaction involving an element and a compound - the lone element must be higher than the one it is trying to replace in the compound on table J
Ex: 2Na + 2HCl ---> 2NaCl + H2

Solubility

The ability of a substance to be dissolved in a solvent

Solute

Substance being dissolved

Solution

A homogeneous mixture of a substance in the same physical state

Solvent

Used to dissolve the solute

Subscript

Small number written below atoms in a chemical formula stating how many atoms of each element are in the molecule

Specific Heat

The amount of heat necessary to raise the temperature of a substance by 1 deg C

Stable Octet

8 Valence electrons in a valence shell

Sublimation

Phase change from a solid directly two a gas

Supersaturated Solution

A solution created by heating and then slowly cooling an extremely large amount of solute in a small amount of solution

Synthesis

Chemical reaction in which smaller elements are combined to make larger products

Temperature

A measure of the average kinetic energy of a substance

Unsaturated Solution

Solution that holds a small amount of solute to a large abound of solvent

Valence Electron

The electrons in the last principal energy level of an atom

Addition Reaction

a reaction in which part of a compound is added to one end of a double or triple bond, while the rest adds to the other end, converting it, respectively, to a single or double bond.

Alcohol

An alcohol is a substance containing an OH group attached to a hydrocarbon group.

Alkalinity

The capacity of water for neutralizing an acid solution.

Allotrope

one of two or more existing forms of an element:
Graphite and diamond are allotropes of carbon.

Alpha Particle

a positively charged particle consisting of two protons and two neutrons, emitted in radioactive decay or nuclear fission; the nucleus of a helium atom.

Amino Acid

An amino acid is a type of organic acid that contains an acid functional group and an amine functional group on adjacent carbon atoms.

Atomic Radius

The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding cloud of electrons.

Battery

a combination of two or more cell electrically connected to work together to produce electric energy.

Beta Particle

An electron or positron. The term is generally applied to an electron or positron emitted in radioactive beta decay.