A neutral atom of an element has `2K,8L ,9M,`and `2N` electon .Find and the following
a. Atomic number
b. Total number of s electron
c Total number of p electron
d.Total number of d electron
e.Valency of the element
f.Number of unpaired electrons

Options

A. 6
B. 12
C. 18
D. 24

Answer

B, D

Explanation

`overset(2K,8L,9M,and,2N)underset(1s^(2),2s^(2)p^(6),3s^(2)3p^(6)3d^(1), 4s^(2))`
`({:(K means n = 1, l means n = 2),(M means n = 3 , N means n = 4):})`
`"Structure is" `3d^(1),4s^(2)`
Atomic number 21
`2p^(6) + 3p^(6) = 12`