| A | B |
|---|
| Atom | Smallest part of matter |
| Atomic Number | Number of protons in its nucleus |
| Average atomic mass | Ave. mass of an element is the ave. mass of the mixture of its isotopes |
| Electron | Neg. charged particles that move around the nucleus of an atom |
| Energy Level | amount of enery in an atom |
| Group | family on periodic table made of similar properties |
| Isotope | Atoms of the same element that have different #s of nuetrons |
| Mass # | sum of number of protons and nuetrons in an atoms nucleus |
| metal | elements usually having these common properties; shiny, good conductors of heat and electricity |
| Metalloid | Elements usually having properties of both metals and non metals |
| Nuetron | Atomic particle with no charge that is part of an atoms nucleus |
| Nonmetal | Elements that usually are gases or brittle solids at room temperature |
| Nucleus | Positively charged center of an atom that contains protons and neutrons |
| Period | Horizontal row on Periodic Table |
| Proton | Particle with positive charge |
