| A | B |
|---|
| atom | the smallest piece of an element that retains the property of the element |
| atomic number | the number of protons in the nucleus |
| average atomic mass | weighted average of the mass of the all isotopes |
| electron | particle with a negative charge |
| electron cloud | area around nucleus where electrons are found |
| electron dot diagram | uses atom symbol and dots to represent the outer electrons |
| group | a vertical column on the periodic table |
| isotope | an atom of the same element with a different number of neutrons |
| mass number | protons + neutrons |
| neutron | particle with no charge |
| nucleus | postively charged center of the atom |
| period | a horizontal row on the periodic table |
| periodic table | organized list of elements arranged according to properties |
| proton | particle with a positive charge |
| quark | smaller particles that make up protons and neutrons |
