| A | B |
|---|
| element | a substance that cannot be broken down into simpler substances by chemical or physical means |
| atomic number | the number of protons in the nucleus of an atom |
| energy level | regions where electrons can exist |
| isotope | atoms with the same number of protons but different numbers of neutrons |
| mass number | the total mass of an atom, also, the total number of protons and neutrons in the nucleus of an atom |
| compound | a substance that consists of two or more elements that are chemically combined in specific proportions |
| chemical bond | forces that hold atoms together in a compound |
| ion | an atom that has an electrical charge because of a gain or loss of one or more electrons |
| ionic bond | bonds that form between positive and negative ions |
| covalent bond | bonds that form when atoms share electrons |
| metallic bond | bonds that form when electrons are shared by metal ions |
| mineral | a naturally occurring, inorganic solid with an orderly crystalline structure and a definite chemical composition |
| silicate | the most common group of minerals on earth, they contain both silicon and oxygen atoms |
| silicon-oxygen tetrahedron | a structure composed of four oxygen atoms surrounding a silicon atom |
| carbonates | minerals that contain the elements carbon, oxygen, and one or more other metallic elements |
| oxides | minerals that contain oxygen and one or more other elements, which are usually metals |
| sulfates and sulfides | minerals that contain the element sulfur |
| halides | minerals that contain a halogen ion plus one or more other elements |
| native elements | minerals that exist in a relatively pure form |
| streak | the color of a mineral in its powdered form |
| luster | used to describe how light is reflected from the surface of a mineral |
| crystal form | the visible expression of a mineralÕs internal arrangement of atoms |
| hardness | a measure of a mineralÕs resistance to being scratched |
| Mohs scale | a standard hardness scale, ranging from 1 (the softest) to 10 (the hardest) |
| cleavage | the tendency of a mineral to break along flat, even surfaces |
| fracture | the uneven breakage of a mineral. |
| density | the ratio of an objects mass to its volume |
