Biology3 ch2

basic structural unit of matter

number of protons in the nucleus

negatively charged subatomic particle

a substance that cannot be broken down

atoms of the same element with different numbers of neutrons

total number of protons and neutrons in the nucleus

uncharged subatomic particle

core of an atom; occupied by protons and neutrons

positively charged subatomic particle

atom that carries a charge because it has an unequal number of protons and electrons

an attractive force that arises between two atoms when their electrons interact

a union of two or more atoms joined in a chemical bond

type of molecule that has atoms of more than one element

type of chemical bond in which a strong mutual attraction forms between ions of opposite charge

chemical bond in which two atoms share a pair of electrons

having an even distribution of charge

having an uneven distribution of charge; a molecule that has an equal number of protons and electrons, but an uneven distribution of electrons across the molecule

any separation of charge into distinct positive and negative regions

attraction that forms between a covalently bonded hydrogen atom and another atom taking part in a separate covalent bond

liquid that can dissolve other substances

a dissolved substance

measure of the number of hydrogen ions in a fluid

describes a substance that dissolves easily in water

describes a substance that resists dissolving in water

measure of molecular motion

tendency of molecules to stick together