Question

In Bohr's model of the hydrogen atom, the pairs of quantities that are quantized among the following is

• A. Energy and linear momentum
• B. Linear and angular momentum
• C. Energy and angular momentum
• D. None of the above

Answer 1

Answer: (C)

According to Bohr's theory of the $H$ atom, electrons can revolve only in those orbits in which their angular momentum is an integral multiple of $\frac{h}{2\pi }$ , where $h$ is Plank's constant.
Angular momentum = $mvr$ = $\frac{2h}{2\pi }$
Hence, angular momentum is quantized.
The energy of an electron in $n^{th}$ orbit of the hydrogen atom,
$E=$ $\frac{Rhc}{n^2}$ $J$
Thus, it is obvious that the hydrogen atom has some characteristics of energy state. In fact, this is true for the atom of each element, $ie,$ each atom has its energy quantized.
Hence, both energy and angular momentum are quantised.