| A | B |
|---|
| Writing Symbols - rules | first letter is capitalized, second letter is lower case (Na) |
| Nucleus | protons and neutrons found here |
| Electrons | move around the nucleus |
| charges | protons(+), electrons (-), neutrons (none) |
| atomic number | identifies number of protons an element has |
| electron cloud model | current model of what we think an atom "looks like" uses dots around nucleus to represent electrons |
| lowest energy level | closest to nucleus |
| highest energy level | furthest from nucleus |
| quark | smaller particles that make up protons and neutrons - there are 6 kinds |
| proton quarks | particular arrangement of 3 quarks |
| tevatron | machine used to collide atoms at high speeds |
| atomic mass | number of protons plus number of neutrons |
| why aren't electrons considered in atomic mass? | electron mass is too small to make a difference |
| How many neutrons in an atom? | Mass number - Atomic number |
| isotope | atoms of same element with different number of neutrons |
| average atomic mass | average of all element's isotopes |
| valence electrons | electrons found in outermost shell |
| magic number of valence electrons? | 8 - every element either wants to combine/give up electrons to achieve this |
| periodic columns | groups |
| periodic rows | periods |
| periodic arrangement of periods | left to right in ascending atomic number order |
| which groups follow the valence electron "trick"? | 1, 2, 13-18 |
| Dalton | solid sphere (golf ball) |
| Thomson | sphere with electrons embedded (blueberry muffin) |
| Rutherford | most mass in center (peach) |
| Bohr | traveling electrons (solar system) |
