If the energy of a photon with a frequency of $2 \times 10^{12} \ Hz$ is $E$,then the energy of a photon with a frequency of $4 \times 10^{12} \ Hz$ will be ....

What is the energy of an electron in the stationary state corresponding to $n=2$?

In which transition is minimum energy emitted?

If the ionization potential of $Li^{2+}$ is $122.4 \ eV$,what is the $5^{th}$ ionization potential of carbon in $eV$?

From the following energy levels of a hydrogen atom, the values of $E_{\infty}$ and $E_3$ in $J$ are, respectively: $E_{\infty} = \ldots \ldots \ldots$ $E_3 = \ldots \ldots \ldots$ Given: $E_2 = -0.545 \times 10^{-18} \ J$, $E_1 = -2.18 \times 10^{-18} \ J$.

The energy of an electron in an excited hydrogen atom is $-3.4 \, eV$. According to Bohr's theory,the angular momentum of this electron in $J \cdot s$ is: