If the electron jumps from $7.00 \ eV$ energy level to $5.0 \ eV$ energy level,it :

The Ritz combination principle states that:

What is the approximate angular momentum (in $J \ s$) of an electron in a hydrogen atom in its ground state? $(h = 6.625 \times 10^{-34} \ J \ s)$

Based on the equation $\Delta E = - 2.0 \times 10^{-18} \, J \left( \frac{1}{n_2^2} - \frac{1}{n_1^2} \right)$,the wavelength of the light that must be absorbed to excite a hydrogen electron from level $n = 1$ to level $n = 2$ will be: $(h = 6.625 \times 10^{-34} \, J \, s, c = 3 \times 10^8 \, m \, s^{-1})$

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

The wavenumber of the first spectral line of the Lyman series of $He^{+}$ ion is $x \ m^{-1}$. What is the wavenumber (in $m^{-1}$) of the second spectral line of the Balmer series of $Li^{2+}$ ion?