2: The Chemistry of Life

basic unit of matter

the center of the atom which contains the protons and neutrons: in cells, structure that contains the cells structure that contains the cell's genetic material (DNA) and controls the cell's activity

negatively charged particle; located outside the atomic nucleus

substance consisting entirely of one type of atom

atom of an element that has a number of neutrons different from that of other atoms of the same element

substance formed by the chemical combination of tow or more elements in definite proportions

bond formed when one or more electrons are transferred from one atom to another

atom that has a positive or negative charge

bond formed by the sharing of electrons between atoms

smallest unit of most compounds

a slight attraction that develops between the oppositely charged regions of nearby moluecules

attraction between molecules of the same substance

attraction between molecules of different substances; in plants, attraction between unlike molecules

material composed of two or more elements or compounds that are physically mixed together but not chemically combined

mixture of two or more substances in which the molecules of the substances are evenly distributed

substance that is dissolved in a solvent to make a solution

substance in which a solute is dissolved to form a solution

mixture of water and nondissolved materials

measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14

compound that forms hydrogen ions (H+) in solution

compound that produces hydroxide ions (OH+) in solution

weak acid or base that can react with strong acids or bases to help prevent sharp, sudden changes in pH