element
a pure substance made of only one kind of atom
atomic number
the number of protons in the nucleus of an atom
mass number
the sum of the number of neutrons and protons in an atomic nucleus
neutron
a subatomic particle that has no charge and that is found in the nucleus of an atom
orbital
a region of space around the nucleus where an electron is likely to be found
periodic table
A table that shows the elements, their atomic number, symbol, and average atomic mass; elements with similar chemical properties are grouped together.
family
(biology) a taxonomic group containing one or more genera
Lewis Diagram
A method of showing the organization of the valence electrons in an atom
phases of matter
solid, liquid, gas, plasma
compound
a substance made up of atoms of two or more different elements joined by chemical bonds
atomic mass
Total mass of the protons and neutrons in an atom, measured in atomic mass units
proton
a subatomic particle that has a positive charge and that is found in the nucleus of an atom
electron
negatively charged particle; located outside the atomic nucleus
valence
the number of electrons in the outermost energy level of an atom
Group Number
numbers may be at the top of each column in the periodic table;gives the valence numder of electrons;columns 13-18 you have to subtract
Bohr Diagram
a diagram of an atom which includes all protons, neutrons, electron shells, and electrons
Elemental Symbol
A one or two letter representation of an element
covalent bonding
A chemical bond resulting from the sharing of an electron pair between two atoms
ionic bonding
bonding that involves a transfer of electrons
structural formula
a chemical formula that shows the arrangement of atoms in a molecule or a polyatomic ion; each dash between a pair of atoms indicates a pair of shared electrons
single covalent
share one pair of electrons
coefficient
A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.
conservation of matter
in any chemical reaction matter changes form; it is neither created nor destroyed.
cohesion
(physics) the intermolecular force that holds together the molecules in a solid or liquid
solvent
substance in which a solute is dissolved to form a solution
phases of water
solid, liquid, gas
electrovalent bonding
ion from one atom transferred to another, creates two ions
hydrogen bonding
attraction between positive charge on a hydrogen in a dipole and the negative end of another molecule. Think water!
molecular formula
shows the types and numbers of atoms combined in a single molecule of a molecular compound
double covalent
share two pairs of electrons
chemical equation
a way to describe a chemical reaction using chemical formulas and other symbols
adhesion
an attraction between molecules of different substances
density of water
1 g/ml
solute
the dissolved substance in a solution
universal solvent
Water- due to its polarity and ability to dissolve many different solutes
capillary action
The attraction of the surface of a liquid to the surface of a solid, which causes the liquid to rise or fall
pH scale
a range of numbers used to describe how acidic or basic a solution is; ranges from 0 (most acidic) to 14 (most basic)
acid
compound that forms hydrogen ions (H+) in solution
buffer
weak acid or base that can react with strong acids or bases to help prevent sharp, sudden changes in pH
neutral
having only a limited ability to react chemically
concentration
the strength of a solution
litmus test
a test that relies on a single indicator
base
any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water
antacid
a weak base that neutralizes stomach acid
neutralize
make chemically neutral
dilute
lessen the strength or flavor of a solution or mixture