| A | B |
|---|
| anything that has mass and occupies space | matter |
| the smallest portion of an element | atom |
| the center part of an atom that contains protons and neutrons | nucleus |
| a particle in an atom found in the nucleus that has a positive electrical charge | proton |
| a particle in an atom found in the nucleus that has no electrical charge | neutron |
| a particle found in an atom that has a negative electrical charge | electron |
| substance that cannot be separated into a simpler substance | element |
| an orderly arrangement of elements based on their atomic numbers | periodic table |
| an element's position in the periodic table based on (and equal to) the number of protons it has in its nucleus | atomic number |
| atoms of the same element that have different numbers of neutrons in the nucleus | isotopes |
| the mass contained in an element's nucleus, which is equal to the number of protons plus the number of neutrons | atomic mass |
| the distance at which electrons travel around the nucleus of an atom | electron energy level |
| a chemical combination of two or more atoms or elements | chemical compound |
| process that occurs when one substance is changed into another | chemical reaction |
| an element's ability or tendency to combine with another element | reactivity |
| tendency of atoms to gain, lose, or share electrons with other atoms in order to have 8 electrons in their outer energy level | octet rule |
| the attractive force between atoms that is formed when atoms transfer or share their electrons | chemical bond |
| a diagram of an atom that represents its valence electrons as dots around the chemical symbol | electron dot diagram |
| a bond formed between a metal and a nonmetal, there is a transfer (gain or loss) of electrons | ionic bond |
| a bond formed between two nonmetals, elements share electrons | covalent bond |
| an electrically charged atom that has gained or lost electrons | ion |
| carbon-containing compounds that make up living tissue | organic compound |
| a molecule that has a partial positive charge on one end and a partial negative charge on the other end | polar molecule |
| the weak bond that occurs between two hydrogens | hydrogen bond |
| the attraction between molecules of the same kind | cohesion |
| the film-like quality on the surface of a liquid that is caused by the attraction of the liquid molecules to themselves | surface tension |
| the attraction of one type of molecule to a different type of molecule | adhesion |
| the tendency of a liquid to draw into a narrow tube due to the liquid's properties of cohesion and adhesion | capillary action |
| the amount of heat needed to raise the temperature of one gram of a substance on degree Celsius | specific heat |
| a substance that dissolves another | solvent |
| a substance that is being dissolved | solute |
| the combination of a solvent and a solute | solution |
| any process that occurs in living organisms | biological process |
| a measure of the acidity or alkalinity of a substance | pH |
| a solution with more hydrogen ions than hydroxide ions; having a pH less than 7 | acid |
| a solution with more hydroxide ions than hydrogen ions; having a pH greater than 7 | base |
| a substance that prevents the pH of a solution from changing even in a small amount of an acid or a base is added | buffer |
