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Atomic
Regents Chem - atomic theory
| Question | Answer |
|---|---|
| Proton | subatomic particle with a positive charge and mass of 1 amu. Found inside the nucleus. |
| Neutron | subatomic particle with neutral charge and a mass of 1 amu. Found inside the nucleus. |
| Nucleon | protons and neutrons (found inside the nucleus) |
| Electron | subatomic particle with a negative charge and no significant mass (1/1836 amu). Located outside nucleus |
| Orbital | In the current atomic model, this is the region outside the nucleus where you have a 90% probability of finding an electron |
| Mass number | protons + neutrons. The top number in an elements notation. |
| Atomic number | # protons (identifies the element) |
| Isotopes | same element (same # protons) but with different numbers of neutrons (different mass). Ex. C-12 and C-14. |
| Ions | elements that have a charge due to the gain or loss of electrons. Gaining electrons creates a negative ion |
| Ground state | electrons are in their lowest energy levels (ie: magnesium, 2-8-2) |
| Excited State | electrons are excited and at least one electron is in a higher than normal energy level (ie: magnesium 2-7-3) |
| Electron configuration | lists the number of electrons in each energy level. Max #’s: 1st level: 2; 2nd level: 8; 3rd level: 18; 4th level: 32 |
| Lewis (Electron) Dot Structure | element symbol with dots around it, representing the valence electrons. 1st 2 electrons are paired and the rest fill uniformly. |
| Rutherford’s Gold Foil Experiment | alpha particles (+2) were aimed at gold foil. Two things were proven: 1-the atom is mostly empty space; 2-there is a dense positive center (nucleus) |
| Bohr Model | model of the atom with the nucleus surrounded by energy levels containing the electrons |
| Wave Mechanical (Electron Cloud) Model | current atomic model. Electrons are located in orbitals (where you have a 90% probability of finding an electron) |
| A negative ion (anion) | has more electrons than protons |
| A positive ion (cation) | has more protons than electrons |
| A neutral atom | # protons same as # electrons |