Question | Answer |
the joining of two atoms to form new substances | chemical bonding |
interaction that holds two atoms together | chemical bond |
what is the number of protons ( and electrons) in an atom? | atomic number |
what are electrons organized in? | energy levels |
what is the electron(s) in the outermost energy level? | valence electrons |
what determines whether the atom will form bonds? | valence electrons |
what is considered a full outer energy level? | 8 |
atoms bond by ---, ---, or --- electrons in the outermost energy level. | gain,lose or share |
do all atoms need 8 electrons to have a full outer energy level? | no |
how does an ionic bond form? | when electrons are transfered from atom to atom |
when is an atom nuetral? | when it has the same number of electrons as protons |
what are charged particles that form when atoms gain or lose electrons? | ions |
nonmetals usually --- electrons | gain |
what is a repeating 3D pattern formed when ions bond? | cyrstal lattice |
what type of charge do ionic compounds have? | none |
what are some properties of covalent bonds? | brittle, low melting and boiling points |
in covalent bonds, atoms --- electrons | share |
what is a molecule? | compound that consists of two or more atoms joined in a definite ratio |
what are electron dot diagrams used to show? | the number of valence electrons in an atom |
diatomic molecules are molecules made up of --- atoms | 2 |
what are diatomic elements? | elements that are found in nature as diatomic molecules |
what is a bond formed from the attraction of metal ions and electrons? | metallic bond |
what are some properties of metal? | ductile, malleable, conduct electric current |
a process in which one or more substances change to make one or more new substances | chemical reaction |
what is a precipitate? | a solid substance that is formed in a solution |
what are some signs of a chemical reaction? | gas formation, precipitate, change in energy |
what is the froce that holds 2 atoms together in a molecule? | chemical bond |
for new bonds to form, the old ones must --- | break |
shorthand way to use chemical symbols and numbers to represent a substance | chemical formula |
what is a subscript? | a number written to below and to the right of a chemical formula in a formula |
tetra= | 4 |
di= | 2 |
deca = | 10 |
hexa= | 6 |
octa= | 8 |
mono= | 1 |
tri= | 3 |
penta= | 5 |
hepta= | 7 |
nona= | 9 |
what uses chemical symbols and formulas as a shortcut to describe a chemical reaction? | chemical formula |
what is a coefficent? | the number that is placed in front of a chemical symbol or formula |
states that mass is neither created or destroyed in ordinary chemical and physical changes | law of conservation of mass |
type of reaction in which two or more substances combine to form one new compound | synthesis reaction |
what reaction is the reverse of a synthesis reaction? | decompostition reaction |
type of reaction in which an element replaces another element that is part of a compound | single-displacement reaction |
what are the products of a single-displacement reaction? | a new compound and a different element |
a type of reaction in which ions from two compounds change places | double-displacement reaction |
what is needed to break chemical bonds in reactants? | energy |
exothermic --- energy and endothermic --- energy | releases; takes in |