| A | B |
|---|
| periodic law | physical and chemical properties of the elements are periodic functions of their atomic numbers |
| periodic table | arrangement of the elements in order o their atmic numbers so that elements with similar properties fall in the same column or group |
| lathanide | 14 elements with atomic numbers from 58 to 71 |
| actinide | 14 elements wit hatomic numbers from 90 to 103 |
| alkali metals | Group 1 of the periodic table, lithium, soium, potassium, rubidium, cesium, and francium |
| alkaline-earth metals | group 2 of the periodic table, beryllium, magnesium, calcium, strontium, barium, and radium |
| transition elements | the d-block elements with typical metallic properties |
| main-group elements | p-block elements together with the s block elements |
| halogens | elments of group 17, flurorine, chlorine, bromine, iodine, and astatine |
| atomic radius | one-half the distance betweenthe nuclei of identical atom that are bonded together |
| ion | atom or group of bonded atoms that has a positive or negative charge |
| ionization | any process that results in the formation of an ion |
| ionization energy | energy required to remove one electron from a neutral atom of an element |
| electron affinity | energy change that occurs when an electron is acquired by aneutral atom |
| cation | positive ion |
| anion | negative ion |
| valence electrons | electrons available to be lost, gained, or shared in the formation of chemical compounds |
| eletronegativity | measure of the ability of an atom in a chemical compound ot attract electrons from another atom in the compound |
