The angular momentum of the $2^{nd}$ Bohr orbit of the $H$ atom is $x$. Find the angular momentum of the $1^{st}$ excited state of $Li^{+2}$.

In the spectrum of $Li^{2+}$,the difference between two energy levels is $2$ and their sum is $4$. Find the wavelength of the photon emitted during the transition between these two energy states.

For a hydrogen atom,which of the following electron transitions requires the highest energy?

The ionization potential of hydrogen atom is $13.6 \ eV$. The energy required to remove an electron from the $n = 2$ state of hydrogen atom is : ............ $eV$

In a $He^{+}$ ion,an electronic transition occurs from orbit $n_2$ to $n_1$ such that:
$2n_2 + 3n_1 = 18$
$2n_2 - 3n_1 = 6$
What is the total number of photons emitted when the electron transitions to the $n_1$ orbit?

The relation between the stopping potential $(V_0)$ and frequency $(v)$ is correctly represented in $[\phi = \text{Work function}]$