The energy of an electron in the first Bohr orbit of a hydrogen atom is $-13.12 \times 10^5 \ J \ mol^{-1}$. Calculate the energy required for the transition of an electron from the first orbit to the second orbit.

When an electric discharge is passed through hydrogen gas,the hydrogen molecules dissociate to produce excited hydrogen atoms. These excited atoms emit electromagnetic radiation of discrete frequencies which can be given by the general formula
$\bar{v} = 109677 \left[ \frac{1}{n_{i}^{2}} - \frac{1}{n_{f}^{2}} \right] \ cm^{-1}$
What points of Bohr's model of an atom can be used to arrive at this formula? Based on these points,derive the above formula,giving a description of each step and each term.

In an orbital,the value of $K.E.$ is equal to:

If the energy of the first orbit of $He^{+}$ is $-54.4 \, eV$,then the energy of the second orbit will be ............. $eV$.

If the electron of a hydrogen atom is present in the first orbit, the total energy of the electron is

What will be the ionization energy in $eV$ for an excited hydrogen atom?