Question

Imagine that there is a maximum 4 electron in a period, then the number of elements
will be in the fifth period.

answer is 36,but how??​

Answer 1

First we need to calculate:

i) No. of subshells ii) No. of orbitals iii) No. of elements

Formula to calculate no. of subshell

1) No. of period is even :

2

(n+2)

2) No. of period is odd :

2

(n+1)

∴

2

(n+2)

⇒n=2

Thus no. of orbitals in various subshell are:

For n=2 we have only s & p orbitals

s has 1 orbital

p has 3 orbital

∴ no. of orbital =4

It is given that each orbital can have a maximum of 3 electrons.

Thus maximum no. of electrons =4×3=12

Hence, the no. of elements = 12

Option D is correct.