The Periodic Table of The Elements

These are called groups or families. Groups are numbered 1-18. Group numbers can help you determine the number of valence electrons: Group 1 has 1 valence electron. Group 2 has 2 valence electrons. Groups 3–12 are transition metals and have 1 or 2 valence electrons. Groups 13–18 have 10 fewer than the group number. For example: ................
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