Question

If K , Land M shells of an element X are completely filled, then element X will be​

Answer 1

Explanation:

An atom of an element (X) has its K, L and M shells filled with some electrons. It reacts with sodium metal to from a compound NaX. The number of electrons in the M shell of the atom (X) will be Seven.

In NaX, Na forms Na

+

and X forms negtive ions. Thus, X gains one electron to form uni negative ion in which octet will be completed. Hence, X has 7 valence electrons

PLEASE MARK AS BRAINLIESTS ❣️

Answer 2

Answer:

Argon

Explanation:

atomic no. of argon is 18

2,8,8

k,l,m