Chemistry EOC Review

activation energy

the minimum amount of energy required by reacting particles in order to form the activated complex and lead to a reaction

alloy

a mixture of elements that has metallic properties

atom

the smallest particle of an element that retains all the properties of that element; is electrically neutral, spherically shaped, and composed of protons, neutrons, and electrons

aufbau principle

states that each electron occupies the lowest energy orbital available

Avogadro's number

the number 6.02 x 10^23 which is representative of the number of particles in a mole

average atomic mass

determined by multiplying each number isotope by the percent, and adding all of the products

anion

an ion that has a negative charge; forms when valence electrons are added to the outer energy level

atomic number

the number of protons in an atom

cation

an ion that has a positive charge; forms when valence electrons are removed, giving the in a stable electron configuration

chemical property

the ability or inability of a substance to comine with or change into one or more new substances

catalyst

a substance that increases the rate of a chemical reaction by lowering the activation energy

coeffecient

the number written in front of a reactant or product

combined gas law

a single law combing boyles, charles, and lussacs laws that states the relationship among pressure, volume, and temp of a fixed amount of gas

combustion reaction

a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light; hydrocarbon + oxygen yields carbon dioxide + water

covalent bond

a chemical bond that results from the sharing of valence electrons; electronegativity difference is less than 1.7; two or more nonmetals

cathode ray

J.J. Thompson's experiment in which he discovered electrons and protons; created the plum pudding model

compound

combination of two or more elements

Dalton's atomic theory

5 part theory; right

Dalton's law of partial pressures

states that the total pressure of amixture of gases is equal to the sum of the pressures of all the gases in the mixtures

decomposition reaction

a chemical reaction that occurs when a single compound breaks down into two or more elemtns or new compounds

delocalized electrons

the electrons involved in metallic bonding that are free to move easily from one atom to the next throughout the metal and are not attached to any particular atom

deposition

when substance changes from gas/vapor to a solid, without first becoming liquid

double replacement reaction

a chemical reaction that involves the exchange of positive ions between two compounds and produces either a precipitate, a gas, or water

dipole

dipole forces

electron

a negatively charged, fast moving particle found in the empty space surrounding nucleus

electron configuration

the arrangement of electrons in an atom

electronegativity

indicates the relative ability of an elements atoms to attract electrons in a chemical bond

element

a pure substance that cannot be broken down into simpler subtances by physical or chemical means

endothermic

a chemical reaction in which a grater amount of energy is required to break the existing bonds than is released when the new bonds form in the product molecules; heat absorbed

exothermic

a chemical reaction in which more energy is released than is required to break bonds in the initial reaction; heat released

heterogenous mixture

one that does not have a uniform composition and in which the individual substances remain distinct

homogeneous mixture

one that has a uniform composition throughout and always has a single pahse; also called a solution

hydrogen bond

a strong dipole dipole attraction bw molecules that contain a hydrogen atom bonded to a small, highly electronegative atom with at least one lone electron pair; usually N, O, F

ideal gas law

PV=nRT; temp in kelvin, R depends on P units

isotopes

atoms of the same element with the same number of protons, but different number of neutrons

ionic bond

metal with a nonmetal; hard, rigid, brittle solids, high melting and boiling points, conducts electricity in the aqueous and molten states

insoluable

describes a substance that cannot be dissolved in a given solvent

ionization energy

the energy required to remove an electrn from a gaseous atom; generally increases left to right, and decreases tope to bottom. (florine=greatest)

joule

the SI unit of heat and enegy

kinetic molecular theory

explains the properties of gases in terms of the energy, size, and motion of thier particles

law of conservation of energy

states that in any chemical or physical process, energy may change from one form to another, but it is neither created, nor destroyed

law of conservation of mass

in any physical change or chemical reaction, mass is conserved; mass can be neither created nor destroyed

Lewis Dot structure

a model that uses electron dot structures to show how electrons are arranged in molecules; lines represent bonding pairs

limiting reactant

reactant that is totally consumed during a chemical reaction, limits the exten of the reaction and dtermines the amount of product

matter

anything that has mass and takes up space

mixture

a physical blend of two or more pure substances in any proportion in which each

molecule

forms when two or more atoms covalently bond and is lower in potential energy than its constituent atoms

mass number

the number after the elements name, representing the sum of its protons and neutrons

metal

left side of periodic table; good conductor of heat and electricity, ductile, malleable, generall shiny

metalloid

an element that has properties of both metals and nonmetals; found along the steps lines on periodic table

metallic bond

the attraction of a metallic cation for delocalized electrons

molecular formula

a formula that specifies the actual number of atoms of each element in one molecule or formula unit of the substance; done after empirical formula

empirical formula

percent to mass, mass to mole, divide by small, multiply till whole

heat of fusion

the amount of heat required to melt one mole of a solid substance; 334j/g; Q=mHf

heat of vaporization

the amount of heat required to evaporate one mole of a liquid; 2260j/g; Q=mHv

molarity

the number of moles of solute dissolved per liter of solution; moles of solute/liters of solution

molar mass

the mass in grams of one mole of any pure substance

molar volume

for a gas, the volume that one mole occupies; 22.4 at one mole

mole

the SI base unit used to measure the amount of a substance

neutron

a neutral subatomic particle in an atoms nucleus that has a mass nearly equal to that of a proton

group

the vertical column of elements in the periodic table

noble gas configuration

electron configuration in which you incorporate the noble gas to replace a group of configurations

neutralization reaction

a reaction in which an acid and base react in aqueous solution to produce a salt and water

nonmetal

elements on the right side of periodic table; generally dull gases, brittle solids, and poor conductors of heat and electricity

octet rule

states that atoms lose, gain, or share electrons in order to acquire a full set of eight valence electrons

Pauli exclusion principle

states that a maximum of two electrons may occupy a single atomic orbital, but only if the electrons have opposite spins

pH

the negative logarithm of the hydrogen ion concentration of a solution; 1

period

a horizontal row of elements in the periodic table

physical change

a type of change that alters the physical properties of a substance but does not change its composition

physical property

A characteristic of a matter that can be observed without changing the samples composition; ex. density, color, taste, etc

photon

a particle of electromagnetic radiation with no mass that carries a quantum of energy

polar covalent

a type of bond that forms when electrons are not shared equally

precipitate

a solid produced during a chemical reactin in a solution

product

a substance formed during a chemical reaction

proton

a subatomic particle in an atoms nucleus with a positive charge a 1+

reactant

the starting substance in a chemical reaction

excess reactant

a reactant that remains after a chemical reactant starts

saturated

contains the maximum amount of dissolved solute for a give amount of solvent at a specific temp and pressure

single replacement reaction

a chemical reaction that occurs when the atoms of one element replace the atoms of another element in a compound

solute

a substance dissolved in a solution

soluble

describes a substance that can be dissolved in a give solvent

solvent

the substance that dissolves a solute to form a solution

solution

a uniform mixture that may contain solids, liquids, or gases

sublimation

solid changes to directly to a gas w/o becoming liquid first

supersaturated

contains more dissolved solute than a saturated solution at the same temperatrue

synthesis reaction

a chemical reaction in which two or more substances react to yield a single product

temperature

a measure of the average kinetic energy of the particles in a sample of matter

unsaturated solution

contains less dissolved solute for a given temp and pressure than a saturated solution

valence electrons

the electrons in an atoms outermost orbitals; determines the elements chem properties

heat

a form of energy that flows from a warmer object to a cooler object

Q=mCpT

specific heat formula