Question

The electronic configuration of an element X is 2, 8, 7
1) What is the group number of X?
2) What is the period number of X?
3) How many valence electrons are there in an atom of
4) What is the Valency of X?
5) Is it a metal or a non-metal?​

Answer 1

Answer:

4) Its valency is 1.

Sorry rest I don't know, but knew this so wrote it.

Answer 2

Answer:

17th group 3rd period 7valence electron , valency of chlorine is -1 and it is a non metal because it has electro negativity property that is to accept electrons