What is the wavenumber of the photon emitted during transition from the orbit $n=5$ to that of $n=2$ in hydrogen atom (in $cm^{-1}$)?
$\left[R_{H}=109677 \ cm^{-1}\right]$

Which of the following equations represents the velocity $(v)$ of the ejected electrons when a metal is struck with light of frequency $\nu$ and the threshold frequency of the metal is $\nu_0$? ($m_e =$ mass of electron and $h$ is Planck's constant).

Write the postulates of Bohr's model of the hydrogen atom.

If an electron moves from an excited state to the ground state in multiple steps in the hydrogen spectrum,and the number of lines in the visible region is $4$,then the number of lines in the infrared region is:

When an electron revolves in a stationary orbit,then:

The ionization energy of a hydrogen atom is $13.6 \ eV$. The energy required to excite the electron in a hydrogen atom from the ground state $(n=1)$ to the first excited state $(n=2)$ is (Note: The question asks for energy per atom in Joules. Given $1 \ eV = 1.602 \times 10^{-19} \ J$)