| A | B |
|---|
| atom | The smallest particle of an element which possesses the properties of that element and is neutrally charged. |
| compound | Two or more different elements bonded together. |
| molecule | Two or more atoms (the same or different) bonded together |
| molecular elements | H2, O2, N2, F2, Cl2, Br2, I2,S8, P4 |
| atomic elements | all except the molecular elements |
| ionic compound | Any combination of a metal and a nonmetal |
| molecular compound | Any compound which only contains nonmetals |
| ions | An atom that has lost an electron (metal) and is + or a nonmetal that has gained an electron and is - |
| empirical formula | formula showing ratio of ions in an ionic compound |
| molecular formula | Formula showing the ratio of atoms in a given molecule |
| coefficient | A number used to multiply the entire formula that follows |
| binary compound | A compound which contains only two different elements....may be ionic or molecular |
| element | One of the 109 or so different kinds of combinations of protons,neutrons and electrons found in our world--may be an atom or an ion |
| physical change | A change (like melting) in which the substance is the same chemically as before. |
| chemical change | A change in which one or more different elements or compounds is formed |
| solution | A mixture of at least two substances which at at the atomic or molecular level |
| mixture | A solution, colloid or ordinary mixture depending upon the sizes of the particles involved |
| colloid | A mixture in which one ingredient is barely larger than atomic/molecular size but is large enough to affect light |
| micrometer | One millionth of a meter (10-6) |
| millimeter | One thousandth of a meter |
| kilometer | One thousand meters |
| nanosecond | One billionth (10-9s) |
| centigram | One hundredth (l0-2) of a gram |
| density | Ratio of mass to volume (M/V) |
| colloidal suspension | Particles reflect light but too small to settle |
| phase change | when a substance changes to another phase: solid,liquid or gas. |
| potential energy | stored energy because of position |
| kinetic energy | energy of motion |
| metals | left side periodic chart; conduct electricity and often form + ions |
| non metals | right side periodic chart; often form - ions |
| noble gases | group 18 relatively inert elements;don't form molecules or ions |
| halogens | very reactive group 17; often form -1 ions |
| alkali metals | very reactive group 1; often form +1 ions |
