In the transition of an electron in an atom,its kinetic energy changes from $y$ to $y/4$. The change in potential energy $(P.E.)$ will be:

In the Balmer series of the hydrogen atom spectrum,which electronic transition causes the third line?

The velocity of an electron in the $3^{rd}$ excited state of $Be^{3+}$ is .......

When an electron with energy $10.8 \,eV$ collides with a hydrogen $(H)$ atom,what will happen?

How much energy is required to ionize a $H$ atom if the electron occupies the $n=5$ orbit? Compare your answer with the ionization enthalpy of the $H$ atom (energy required to remove the electron from the $n=1$ orbit).

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: $(h = 6.625 \times 10^{-34} \, J \, s, c = 3 \times 10^8 \, m \, s^{-1})$