Modern Physics 7 Question 37
39. If elements with principal quantum number $n>4$ were not allowed in nature, the number of possible elements would be
$(1983,1 M)$
(a) 60
(b) 32
(c) 4
(d) 64
Show Answer
Solution:
- The maximum number of electrons in an orbit are $2 n^{2}$. If $n>4$, is not allowed, then the number of maximum electrons that can be in first four orbit are :
$$ 2(1)^{2}+2(2)^{2}+2(3)^{2}+2(4)^{2}=2+8+18+32=60 $$
Therefore, possible elements can be 60 .
