The energy required to excite an electron from the $1^{st}$ to the $3^{rd}$ Bohr orbit in $Li^{++}$ is ...... $eV$.

In a hydrogen atom,two electrons are in orbits of radii $r_0$ and $4r_0$. What is the ratio of their frequencies of revolution around the nucleus?

If $E$ and $L$ denote the magnitude of total energy and angular momentum of a revolving electron in the $n^{\text{th}}$ Bohr orbit,then:

$A$ sample of hydrogen-like atoms produces an emission spectrum consisting of $10$ wavelengths arising from all possible transitions. During this process,the maximum angular momentum change for an electron transitioning from a higher energy level to a lower energy level is:

The ratio of radii of $3^{\text{rd}}$ and $6^{\text{th}}$ Bohr's orbit in a hydrogen atom is

Which state of triply ionised Beryllium $(Be^{+++})$ has the same orbital radius as that of the ground state of hydrogen?