This is the Periodic Table of all the elements that have been discovered to date (click on the image to see a larger version).
The Periodic Table is separated in horizontal rows called periods and vertical columns called groups.
- Group 1 (the first column) metals are the Alkali Metals. There are many similarities between them, but they are not identical. From top to bottom the alkali metals are: Lithium, Sodium, Potassium, Rubidium and Caesium. As we move down Group 1 the reactivity of the alkali metals increases. All alkali metals produce a metal hydroxide when they react with water. The general chemical equation is:
alkali metal + water → metal hydroxide + hydrogen
- Group 2 metals show a different trend than that of the alkali metals. Magnesium and Calcium burn vigorously in air producing different-colour bright flames. Metals also react with acids and give similar products; these reactions are dealt with in other worksheets.
- Group 7 elements are called the Halogens (salt formers), when they react with metals.
- Group 8 elements are called the Noble Gases. In the Periodic Table above the Noble Gases are shown as Group 18 and sometimes they are called Group 0 elements. The Noble Gases are generally very unreactive.
The patterns in the Periodic Table exist because of the structure of the elements. Atoms of elements have a nucleus with protons and neutrons, and electrons orbit the nucleus in shells. Elements in the same groups have the same number of electrons in their outer shells. This determines their reaction patterns.