Ncert Exercises & Solutions

Out of the following pairs of electrons, identify the pairs of electrons present in degenerate orbitals.

1. (i) $n = 3, l = 2, m_{l} = - 2, m_{s} = - \frac{1}{2}$ (ii) $n = 3, l = 2, m_{l} = - 1, m_{s} = - \frac{1}{2}$

2. (i) $n = 3, l = 1, m_{l} = 1, m_{s} = + \frac{1}{2}$ (ii) $n = 3, l = 2, m_{l} = 1, m_{s} = + \frac{1}{2}$

3. (i) $(i) n = 4, l = 1, m_{l} = 1, m_{s} = + \frac{1}{2}$ (ii) $n = 3, l = 2, m_{l} = 1, m_{s} = + \frac{1}{2}$

4. (i) $n = 3, l = 2, m_{l} = + 2, m_{s} = - \frac{1}{2}$ (ii) $n = 3, l = 2, m_{l} = + 2, m_{s} = + \frac{1}{2}$

(a, d)

Degenerate orbitals means the orbitals of the same subshell of the same mains hell, i.e., their n and l value.

(a) (i)

3 d_{xy}

(ii)

3 d_{yz}

(b) (i)

3 p_{x}

(ii)

3 d_{xy}

4 s

(ii)

3 d_{xy}

(d) (i)

4 d_{x^{2} - y^{2}}

(ii)

3 d_{x^{2} - y^{2}}

Thus,

3 d_{xy}

and

3 d_{yz}

;

3 d_{x^{2} - y^{2}}

and

3 d_{x^{2} - y^{2}}

represent pair of degenerate orbitals.