Energy of an electron (in $eV$) in the $2^{nd}$ orbit of a $He^{+}$ ion is (in $.6$)?

The following diagram indicates the energy levels of a certain atom. When the system moves from the $2E$ level to the $E$ level,a photon of wavelength $\lambda$ is emitted. The wavelength of the photon produced during its transition from the $\frac{4E}{3}$ level to the $E$ level is

What is an emission line?

$A$ $12.5 \text{ eV}$ electron beam is used to bombard gaseous hydrogen at ground state. The energy level up to which the hydrogen atoms would be excited is:

Which energy level of the singly ionized carbon atom has the same energy as the ground state energy of the hydrogen atom?

When an electron in the ground state of a hydrogen atom is given $12.4 \, eV$ of energy,to which orbit will it transition?