Chapter 5 - The Periodic Law

A: Period and Blocks on the Periodic Table. Vertical columns (group or family) have similar chemical properties. Horizontal rows are series or periods. 1st period 2 elements filling s sublevel. 2nd period: 8 elements filling s and p sublevel. 3rd period: 8 elements filling s and p sublevel. 4th period: 18 elements filling s and d and p ... ................
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