Bohr’s atomic theory gave the idea of :

The most probable radius (in $pm$) for finding the electron in $He^{+}$ is

Assertion : Angular momentum of an electron in any orbit is given by angular momentum $= \frac{nh}{2\pi}$,where $n$ is the principal quantum number.
Reason : The principal quantum number,$n$,can have any integral value.

Explain the photoelectric effect.

Two series of spectral lines of atomic hydrogen which do not belong to the infrared spectral region are

An excited hydrogen atom emits light in the ultraviolet region at a frequency of $2.47 \times 10^{15} \ Hz$. Calculate the energy of a single photon. (Given: $h = 6.63 \times 10^{-34} \ J \cdot s$)