Terms : Hide Images
| 2830730672 | Atomic Number | The number of protons in the nucleus of an atom |  | 0 |
| 2830731491 | periodic law | the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements |  | 1 |
| 2830731492 | group | A column on the periodic table | | 2 |
| 2830732309 | period | A horizontal row of elements in the periodic table |  | 3 |
| 2830733165 | representative element | Elements from groups 1, 2, and 13-18 |  | 4 |
| 2830733794 | transition element | Elements in groups 3-12 |  | 5 |
| 2830733795 | metal | Elements that are good conductors of heat and electric current. |  | 6 |
| 2830735111 | alkali metal | Group 1 elements |  | 7 |
| 2830735921 | alkaline earth metal | Group 2 elements |  | 8 |
| 2830735922 | transition metal | Elements in groups 3-12 | | 9 |
| 2830736997 | inner transition metal | Lanthanides and Actinides |  | 10 |
| 2830737006 | lanthanide series | the rare-earth elements with atomic numbers 57 through 71; having properties similar to lanthanum. |  | 11 |
| 2830739193 | actinide series | period seven elements that are radioactive |  | 12 |
| 2830739194 | nonmetal | elements that are generally gases or brittle dull-looking solids, they are poor conductors of heat and electricity |  | 13 |
| 2830739645 | halogen | Group 17 elements, highly reactive |  | 14 |
| 2830739646 | noble gas | Group 18 elements, extremely unreactive |  | 15 |
| 2830740360 | metalloid | have physical and chemical properties of metals and nonmetals, silicon is an example |  | 16 |
| 2830810805 | valence electron | Electrons on the outermost energy level of an atom |  | 17 |
| 2830824250 | ion | an atom or a bonded group of atoms that has a positive or negative charge |  | 18 |
| 2830825082 | ionization energy | the energy required to remove an electron from a gaseous atom |  | 19 |
| 2830825083 | octet rule | States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons |  | 20 |
| 2830825887 | electronegativity | A measure of the ability of an atom in a chemical compound to attract electrons |  | 21 |
