| A | B |
|---|
| Periodic Table | arrangement of elements in order of their atomic numbers so that elements with similar electrons are located in the same column |
| Periodic Law | natural law that states that the physical and chemical properties of the elements are periodic functions of their atomic numbers |
| group | vertical column of the periodic table that contians elements with similar electon configurations; also known as a family |
| family | vertical column of the periodic table that contains elements with similar electron configurations; also known as as a group |
| period | horizontal row of elements in the periodic table |
| Alkali Metal | element in Group 1A or 1 of the periodic table |
| Alkaline Earth Metal | element in Group 2A or 2 of the periodic table |
| Halogen | reactive, nonmetallic element in Group 7A or 17 of the periodic table |
| Noble Gas | inactive element in group 8A or 18 of the periodic table |
| Metal | element that has a high melting point, is ductile, malliable,shiny, a good conductor of heat and electricity; found on the left side of the periodic table |
| Nonmetal | element that has a low boilin point and a dull surface, breaks easily, is a poor conductor of heat and electricity and tends to gain electrons in a chemical reaction; found on the right side of the periodic table |
| Semimetal | Element that has a mix of metalic and nonmetalic properties; found along the staircase line on the periodic table |
| Valence Electron | electron(s) in the outermost energy level of an atom |
| Abbreviated electron configuration | shorthand notation describing the distribution of electrons among the energy levels of an atom |
| Noble gas inner core | group of electrons in an atom's inner filled energy levels |
| periodic trend | property of the elements that can be predicted from the from the arrangement of the periodic table |
| atomic radius | distance between the center of the nucleus of an atom and the outermost electrons |
| ionization energy | energy required to remove the most loosely held electron from an atom |
| electron affinity | energy change that occurs when an atom gains an electron |
| Electronegativity | property of an element that indicates how strongly an atom of that element attracts electrons in a chemical bond |
