| A | B |
|---|
| Chemical Symbol | A short-hand way to write the name of a element. EX. C for carbon |
| Nucleus | The positively charged center of an atom that contains protons and neutrons. |
| Electron | Negatively charged particles that move around the nucleus of an atom. |
| Proton | Atomic particles with a positive charge that is part of an atoms nucleus. |
| Neutron | Atomic particle with no charge( neutral) that is part of an atoms nucleus. |
| Atomic Number | The number of protons in an atoms nucleus. |
| Electron Cloud | Region where electrons most probably are found surrounding the nucleus of an atom. |
| Quark | Very small particles of matter that make up protons and neutrons. |
| Mass Number | Sum of the number of protons and neutons in an atoms nucleus. |
| Isotope | Atoms of the same element that have different numbers of neutrons. EX boron-10 and boron-11. |
| Average Atomic Number | The average mass of an element is the average mass of the mixture of its isotopes. |
| Periodic table | Table of the elements arranged according to repeated changes in properties. |
| Group | The 18 verticle columns of elements in the periodic table, |
| Dot Diagram | Diagram to represent electrons in the outer energy level of an atom; uses the element symbol and dots. |
| Period | Horizontal row in the periodic table. |
| Metal | Element usually having these properties:shiny, good conductor of heat and electricity' solids at room temperature. In the periodic table, metals are found at the left of the stair-step line. |
| Nonmetal | Elements that are usually gases or brittle solids at room temperature; most do not conduct heat/electricity well. In periodic table, are found at the right of the stair-step line. |
| Metalloid | Elements having properties of both metals and nonmetals. In the periodic table, metalloids are found along the stair-step line that separates metals from nonmetals. |
