| A | B |
|---|
| acid | a substance that produces hydrogen ions in aqueous solutions |
| atomic number | number of protons in the nucleus of a element |
| atomic mass | unit of mass that is 1 1/2 of the mass of a carbon 12 atom |
| average atomic mass | average the masses of all the isotopes of an element |
| chemical bond | the force that holds atoms together in compounds |
| energy levels | three-dimensional volume in which electrons travel around the nucleus |
| electron | negatively charged particle that occupies the space around the nucleus of an atom |
| element | pure substance that can not be broken down |
| hydrated | a term used that has a specific number of water molecules boned to each and attached to water |
| isotopes | atoms of an element that are chemically similar but have different numbers of neutrons and thus, different mass numbers |
| greenhouse gas | a gas that prevents some of the heat produced by solar radiation from leaving the atmophere |
| global warming | a gradual increase in the average temperature of Earth's atmosphere |
| fossil fuel | a fuel that is formed over geologic time by the action of pressure and heat on organic materials |
| fraction | one component of a substance that has been refined by fractional distillation |
| isotopes | atoms of an element that are cheically similar but have different molecular arrangements and properties |
| mass percent | the mass of an element in a compound, expressed as a percent of the compound's total mass |
| mixture | a combination of two or more kinds of matter, in which each component retains its own characteristics |
| pH scale | scale that is used to express the concentration of hydronium ions in a solution as a number from0 - 14 |
| neutron | an uncharged subatomic particle in the nucleus of an atom |
| nucleus | the central core of an atom, composed of protons and neutrons |
