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atom stack
| Term | Definition |
|---|---|
| Democritus | thought of atoms (atomos... etc) |
| aristotle | said matter was continuous |
| 1790 Joseph lois proust | law of definite masses |
| law of definite masses | masses of chemical substances combine in definite repeatable ratios when forming compounds |
| John Dalton | heat envelope |
| jj thompson | plum pudding |
| rutherford | nuclear model |
| chadwick | discovered nuetrons |
| Niels Bohr | planetary model (electron energy levels) |
| quantum models | e clouds orbit |
| orbitals | quantum model |
| orbits | planetary model |
| nuetrons | biggest |
| different numbers of nuetrons | isotopes |
| mass number | protons+nuetrons |
| octet rule | atom is happiest with 8 valence electrons |
| atomic mass | mass of atom measured im AMU's |
| nuclear radiation | emission of rays or particles from unstable nuclei |
| alpha particle | 2 protons and 2 nuetrons (positively charged) |
| beta particle | free electron (nuetron also changes to proton) |
| gamma rays | em waves |
| half life | how long it takes for a half of a sample to decay |