| A | B |
|---|
| mass number | protons plus neutrons |
| fission | splitting of an atom |
| fusion | two small atoms combining |
| alpha particle | same as a He atom, weakest |
| neutral atom | protons = electons |
| atom | smallest part of element still with element's properties |
| law of conservation of matter | matter is neither created nor destroyed |
| gamma radiation | strongest, stoped by 3 inches of lead |
| radioactivity | release of particles when unstable nucleus breaks down |
| proton | posivite, 1 amu |
| neutron | neutral, 1 amu |
| electron | negative, 0 amu |
| atomos | indivisble |
| law of definite proportions | ratio of elements in a compound is always the same |
| nucleus | center of atom, protons and neutrons |
| isotopes | same number of protons but different number of neutrons |
| atomic number | number of protons |
| atomic mass | weighted average of the masses of the element's isotopes |
| one AMU | one-twelfth the mass of C-12 |
