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58 Cards in this Set

  • Front
  • Back
the study of the composition, structure, and properties of matter and the changes it undergoes
smallest unit of an element that maintains the properties of that element
a measure of the amount of matter
a pure substance made of only one kind of atom
a substance that is made from the atoms of two or more elements that are chemically bonded in a definite ratio
a system
what is under study; not the surroundings
scientific guess
a representation of something that can't easily be viewed directly
an explanation of observed phenomena which has been tested and verified
a quantity
something that has magnitude, size, or amount
the law of conservation of mass
mass is neither created nor destroyed during ordinary chemical or physical reactions
the law of definite proportions
a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound
the law of multiple proportions
if two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers
atomic number
the number of protons in the nucleus of each atom of that nucleus
atoms of the same element that have different masses
mass number
the total number of protons and neutrons in the nucleus of an isotope
a general term for any isotope of any element
atomic mass unit
exactly 1/12 the mass of a carbon-12 atom
average atomic mass
the weighted average of the atomic masses of the naturally occurring isotopes of an element
the amount of a substance that contains as many particles as there are in exactly 12 grams of carbon-12
electromagnetic radiation
a form of energy that exhibits wavelike behavior as it travels through space
the distance between corresponding points on adjacent waves
the number of waves that pass a given oint in a specific time, usually one second
the photoelectric effect
the emission of electrons from a metal when light shines on the metal
a quantum
the minimum quantity of energy that can be lost or gained by an atom
a photon
a particle of electromagnetic radiation having zero rest mass and carrying a quantum of energy
the quantum theory of the atom
it describes mathematically the wave properties of electrons and other very small particles
heisenberg uncertainty principle
it is impossible to determine simultaneously both the position and velocity of an electron or any other particle
an orbital
a three-dimensional region around the nucleus that indicates the probably location of an atom
quantum numbers
specify the properties of atomic orbitals and the properties of electrons in orbitals
an electron configuration
the arrangement of electrons in an atom
the aufbau principle
an electron occupies the lowest-energy orbital that can receive it
the pauli exclusion principle
no two electrons in the same atom can have the same set of four quantum numbers
hund's rule
orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin
periodic law
the physical and chemical properties of the elements are periodic functions of their atomic numbers
the periodic table
an arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column or group
atomic radius
1/2 of the distance between the nuclei of identical atoms that are bonded together
ionization energy
the energy required to remove one electron from a neutral atom of an element
a measure of the ability of an atom in a chemical compound to attract electrons
a positive ion
a negative ion
a chemical bond
a mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together
nonpolar covalent bond
a covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge
polar covalent bond
a covalent bond in which the bonded atoms have an unequal attraction for the shared electrons
a neutral group of atoms that are held together by covalent bonds
chemical formula
indicates the relative numbers of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts
molecular formula
shows the types and numbers of atoms combined in a single molecule of a molecular compound
diatomic molecule
a molecule containing only two atoms
the octet rule
chemical compounds tend to form so that each atom, by gining, losing, or sharing electrons, has an octet of electrons in its highest occupied energy level
structural formula
indicates the kind, number, arrangement, and bonds but not the unshared pairs of the atoms in a molecule
single covalent bond
a covalent bond prodced by the sharing of one pair of electrons between two atoms
double covalent bond
a covalent bond produced by the sharing of two pairs of electrons between two atoms
triple covalent bond
a covalent bond produced by the sharing of three pairs of electrons between two atoms
ionic compound
composed of positive and negative ions that are combined so that the numbers of positive and negative charges are equal
a formula unit
the simples collection of atoms from which an ionic compounds formula can be established
polyatomic ion
a charged group of covalently bonded atoms
metallic bonding
the chemical bonding that results from the attraction betwen metal atoms and the surrounding sea of electrons
VSEPR theory
repulsion between the sets of valence-level electrons surrounding an atom causes these sets to be oriented as far apart as possible