Question

4
An element 'X' gains one electron. The electronic configuration of 'X' and the group to which it
belongs will be
(a) 2, 8, 1 and group 17
(b) 2, 8, 7 and group 1
(c) 2, 8, 8, 1 and group 1
(d) 2, 8, 7 and group 17
​

Answer 1

Answer:

Option B is correct

Explanation:

We have Four shells K L M N

First shell have 2 electron

2nd Shell have 8 electron

it gain one electron not loose

so option B is correct

Answer 2

Answer:

option (d) is correct.

Explanation:

Since X gains electrons, it is a non-metal and must have 4 or more electrons in it's valence shell. This eliminates option (a) ad (c).

Now, we must be careful because Group 1 has only strong metals like sodium while 17 has strong non-metals like chlorine.This eliminates option (b). Thus our answer is option (d) .i.e. , 2,8,7 and group 17.