Question

how can the valency of an element to be determined if its electronic configurations is known? what wil be the valency of an element of atomic nine

Answer 1

To determine the valency we look at the no. Electrons in the last/valence shell
If :1,2,3 that is the valency
If: 5,6,7 subtract the number from 8,the difference is the valency

Atomic number 9
E.C =2,7
8-7=1
Therefore valency =1

Answer 2

The vznecy can be determined by the valence shell electrons.
As the atomic no 9 .
Confg - 2'7
Thus as in the last shell only 8 electrons can be accomodate .
- but easy for fluorine to gain one rather than lose 7 .
Thus the valency is 1 .

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