| A | B |
|---|
| Actinides | Radioactive elements with atomic numbers from 90 to 103. |
| Alkali Metals | Elements that are found in Group 1 of the periodic table which are highly reactive with water. |
| Alkaline Earth Metals | Elements that are found in Group 2 of the periodic table which are extremely strong and found in most elements on Earth. |
| Anion | A negative ion. |
| Atomic Radius | Half of the distance between the nuclei of identical molecules. |
| Cation | A positive ion |
| Electron Affinity | The energy change that occurs when an electron is acquired by a neutral atom. |
| Electronegativity | The measure of how well a chemical compound can attract electrons. |
| Halogens | Group 17 elements which are highly reactive. |
| Ion | An element with a positive or negative charge because of an unequal balance of protons and electrons. |
| Ionization | The name of the process that results in an ion. |
| Ionization Energy | The energy required to remove one electron from an element. |
| Lanthanides | Rare earth metals are the 14 elements with atomic numbers from 58 to 71. |
| Main-Group Elements | The S and P block elements grouped together. |
| Periodic Law | The physical and chemical properties are directly related to the atomic number. |
| Periodic Table | An arrangement of electrons in their atomic order with similar properties falling into columns. |
| Transition Elements | D Block metals that have typical metal properties. |
| Valence Electrons | Electrons that are available to lost, gained, or shared in chemical compounds. |
