The light of wavelength $242 \, nm$ is required to remove an electron from a $Na$ atom. What is the ionization energy of the sodium atom in $kJ \, mol^{-1}$?

What will be the frequency of the radiation emitted when an electron in a hydrogen atom jumps from $n = 4$ to $n = 1$? $(h = 6.625 \times 10^{-34} \,J \cdot s)$

Which of the following electronic transitions in a hydrogen atom will require the largest amount of energy?

The radius of which of the following orbits is the same as that of the first Bohr's orbit of the hydrogen atom?

Calculate the energy of an electron in the first four orbits of a hydrogen atom in $kJ \, mol^{-1}$ (Given: $N_A = 6.02 \times 10^{23} \, mol^{-1}$,Rydberg constant $R_H = 2.18 \times 10^{-18} \, J$).

The ratio of the lowest energy in terms of wave numbers of the Balmer and Lyman series of lines of the atomic spectrum of hydrogen is