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Question
Give a reason for the following:
A transition from metallic to non-metallic elements is seen on moving from left to right in a period of the periodic table.
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Solution
In a period valence electrons increase from 1 to 7. But the shell remains the same. The element having valence electron 1, 2, 3 loose electrons, and are metals on the left. And elements having 5, 6, 7 valence electrons gain electrons and become non – metals are on the right of the periodic table.
Hence the transition from metallic to non-metallic character is seen from left to right a period.
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