Assertion: The angular momentum of e- in $4f$ orbital is $\sqrt{3}\frac{h}{\mathrm{\pi }}$.

Reason: Angular momentum of electron in 4th orbit is $\frac{2h}{\pi }$.

The absorption or emission of energy in distinct packets or quanta is referred to as electron quantization. Instead of following a smooth or continuous curve, the intensity of electromagnetic radiation steps up or down from one quantized level to the next as it grows or declines.