Question 14
The electronic configurations of the elements A, B and C are given below. Answer the question on the basis of these configurations.
A 1s2 2s2 2p6
B 1s2 2s2 2p6 3s2 3p3
C 1s2 2p6 2p6 3s2 3p5
Stable form of A may be represented by the formula
(a) A
(b) A2
(c) A3
(d) A4
Answer: (a). A.
The stable form of electronic configuration is ns2 np6 . A represents noble gas because the octet is complete.
A is Neon which has the atomic number 10, the electron configuration is, 1s2 2s2 2p6.