| A | B |
|---|
| nucleus | central core of atom;containing protons and usually neutrons |
| proton | positively charged particle found in nucleus |
| neutron | neutral particle in nucleus |
| electron | tiny,negatively charged particle that moves around nucleus |
| atomic number | the number of protons in the nucleus of an atom |
| isotope | an atom with the same #of protons, different # neutrons |
| mass number | sum of total # protons and neutrons (Ex. carbon - 14) |
| model | diagram,mental picture,mathematical statement or object that represents idea |
| atomic mass | average mass of all the isotopes of an element |
| periodic table | chart of the elements showing repeating pattern of their properties |
| chemical symbol | one or two letter representation of an element |
| period | horizontal row of elements in periodic table |
| group | elements in same vertical column of periodic table; also called family |
