Select the incorrect graph for the velocity of an electron $(e^-)$ in an orbit vs. $Z$,$\frac{1}{n}$,and $n$.

If the first ionization energy of $H$ atom is $13.6 \ eV,$ then the second ionization energy of $He$ atom is (in $eV$)

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).

Which of the following orders is $NOT$ correct for the $1^{st}$,$2^{nd}$,and $3^{rd}$ orbits of a hydrogen-like atom?

For a hydrogen atom,the energy of an electron in the first excited state is $-3.4 \ eV$. The kinetic energy $(KE)$ of the same electron in the hydrogen atom is $x \ eV$. The value of $x$ is . . . . . . $\times 10^{-1} \ eV$. (Nearest integer)

The wavelength of a spectral line for an electronic transition is inversely related to