| A | B |
|---|
| mass | amount of matter in an object |
| atomic number | number of protons in nucleus |
| mass number | protons plus neutrons |
| isotope | atom of same element different number of neutrons |
| average atomic mass | average mass of naturally occuring isotopes of atom |
| chemical property | any characteristic of substance that indicates changeability |
| periodic table | organized list of elements arranged by increasing atomic number and changes in chemical & physical properties |
| period | horizontal row on periodic table |
| group | vertical column in periodic table |
| electron dot diagram | element chemical symbol surrounded by dots (electrons) in outer energy level |
