If in nature there may not be an element for which the principal quantum number n > 4, then the total possible number of elements will be

(a) 60                    (b) 32
(c) 4                      (d) 64

(a) For n=1, maximum number of states = $2{\mathrm{n}}^{2}$ = 2 and for n = 2, 3, 4, maximum number of states would be 8, 18, 32 respectively, Hence number of possible elements
= 2 + 8 + 18 + 32 = 60.

Difficulty Level:

• 57%
• 23%
• 4%
• 17%