Question

An element has atomic no.17 what is the velency of this element & how much valanced electrons does it have

Answer 1

At. No. is 17.
=>Electronic configuration —> 2,8,7

=>Valence electrons = 7.
=>Valency = 8-7 = 1.




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Answer 2

Well, It's Chlorine.

Valency of this element is 1 and it has 7 valence electrons.

Note: Valency is not used to write more than 4.so we can't say that it's valency is 7:)