| A | B |
|---|
| alkali metal | Group 1 (1A) elements, except for hydrogen, that are on the left side of the modern periodic table |
| alkaline earth metal | Group 2 (2A) elements in the modern periodic table |
| electronegativity | indicates the relative ability of an element's atoms to attract electrons in a chemical bond |
| group | a vertical column of elements in the periodic table: also called a family |
| halogen | a highly reactive group 17 (7A) element |
| inner transition metal | a type of group B element that is contained in the f-block of the perioidc table |
| ion | an atom or bonded groups of atoms with a positive or negative charge |
| ionization energy | the energy required to remove an electron from a gaseous atom |
| metal | an element that is solid at room temperature, a good conductor of heat and electricity, and generally is shiny; most metals are ductile and malleable |
| metalloid | an element, such as silicon or germanium, that has physical and chemical properties of both metals and nonmetals |
| noble gas | an extremely unreactive group 18 (8A) element |
| nonmetals | elements that are generally gases or dull, brittle solids that are poor conductors of heat and electricity |
| octet rule | states that atoms lose, gain, or share electrons in order to acquire a full set of eight valence electrons |
| period | a horizontal row of elements in the modern periodic table |
| periodic law | states that when the elements are arranged by increasing atomic number, there is a periodic repetition of their chemical and physical properties |
| representative element | groups 1,2 and 13-18 |
| transition elements | groups 3-12 on the periodic table |
| transition metal | groups 3-12 on the periodic |
