Groups of the Periodic Table
Alkali Metals Group 1a one valence electron Very reactive! React with moisture in air—stored under oil or kerosene Form H 2 in water--fire Form a basic solution in water Soft metal Can cut with knife Tarnish rapidly
Alkaline Earth Metals Group 2A 2 valence electrons Reactive, but not as reactive as Alkali Metals Found in minerals Essential for bones, nerve impulses
Transition Metals B Group d-block Harder metals Form positive ions with a varying charge Can’t tell number of valence electrons Colorful solutions Gemstones-chromium: red; titanium and cobalt: blue Found free (uncombined) in nature Gold and silver Coinage metals
Halogens Group 7A 7 valence electrons Very reactive nonmetals Form negative ions Group has gases, a liquid and a solid Ions important to human body
Noble Gases Group 8A Contain a full outer shell 8 valence electrons Except He has only 2—still full! Very unreactive Also called Inert Gases Can be used in areas to prevent combustion