The diagram shows the lowest four energy levels for an electron in a hypothetical atom. The electron is excited to the $-1\, eV$ level and transitions to the lowest energy state by emitting exactly two photons. Which of the following energies could not belong to either of the photons (in $, eV$)?

The potential energy of the orbital electron in the ground state of a hydrogen atom is $-E$. What is its kinetic energy?

$A$ hydrogen sample is prepared in a particular excited state $A$ of quantum number $n_A=3$. The ground state energy of the hydrogen atom is $-|E|$. Photons of energy $\frac{|E|}{12}$ are absorbed by the sample,which results in the excitation of some electrons to an excited state $B$ of quantum number $n_B$. The value of $n_B$ is:

If the ionisation energy for the hydrogen atom is $13.6 \ eV$,then the energy required to excite it from the ground state to the next higher state is nearly: (in $eV$)

The energy of a hydrogen atom in its ground state is $-13.6 \ eV$. The energy of the level corresponding to the quantum number $n = 2$ (first excited state) in the hydrogen atom is......$eV$.

The total energy of an electron in an orbit of a hydrogen atom is $E$. The potential energy of the electron in the same orbit is: