Explain the postulates and shortcomings of Bohr's atomic model.

a)

i) Postulates of Bohr's atomic model:

• Electrons revolve around the nucleus in specific circular orbits called stationary states without radiating energy.
• Electrons can only exist in orbits where their angular momentum is an integral multiple of $\frac{h}{2\pi}$, i.e., $mvr = n\frac{h}{2\pi}$, where $n$ is a positive integer.
• Energy is absorbed when an electron jumps from a lower energy orbit to a higher energy orbit, and energy is emitted when it jumps from a higher energy orbit to a lower energy orbit. The energy difference is given by $\Delta E = E_2 - E_1 = h\nu$.

ii) Shortcomings of Bohr's atomic model: