Question

What is meant by the statement ‘Angular momentum of an orbiting electron is quantised’?

Answer 1

When an electron's angular momentum is quantized, it means that it can only rotate about the nucleus in orbits where its angular momentum is an integral multiple of `h/2 pi`, where h is Planck’s constant.

Angular momentum of electron  (L) = mvr = `(nh)/(2 pi)`

Where n is an integer and is called the principal quantum number.