Question

What is the valency of magnesium with atomic no. 12 and chlorine with atomic no. 17?

Answer 1

valency of magnesium with atomic no. 12 and chlorine with atomic no. 17 is +2 and -1.

Answer 2

hey mate.
here is the answer.
As we know that atomic number of magnesium is 12.
therefore its electronic configuration is 2,8,2 so it cannot gain 6 electrons to complete its octet and so it loses 2 electrons and becomes positively charged.So its valency now becomes +2.

atomic number of chlorine is 17 so electronic configuration of chlorine is 2,8,7. It is easy to gain one electron and become negatively charged. so its valency becomes -1.

hope it helps.
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