Ncert Exercises & Solutions

2.31 How many electrons in an atom may have the following quantum numbers?

(a) n = 4, ms = – ½ (b) n = 3, l = 0

(a) Total number of electrons in an atom for a value of n = $2 n^{2}$
$∴$ For n = 4,
Total number of electrons = 2 (4)2 = 32
The given element has a fully filled orbital as $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{10}$ .
Hence, all the electrons are paired.
$∴$ Number of electrons (having n = 4 and m, $= - \frac{1}{2}$ ) = 16

(b) n = 3, l = 0 indicates that the electrons are present in the 3s orbital. Therefore, the number of electrons having n = 3 and l = 0 is 2.

NEET Information

courses

Company

Botany Questions

Chemistry Questions

Physics Questions

Zoology Questions