In a hydrogen atom, the energy of an electron in the first and third orbits is $E_1$ and $E_3$ respectively. If $E_3 = x E_1$, then the value of $x$ will be:

The following diagram indicates the energy levels of a certain atom. When the system moves from the $4E$ level to the $E$ level,a photon of wavelength ${\lambda _1}$ is emitted. The wavelength of the photon produced during its transition from the $\frac{7}{3}E$ level to the $E$ level is ${\lambda _2}$. The ratio $\frac{{{\lambda _1}}}{{{\lambda _2}}}$ will be:

In the hydrogen atom,if the reference level of potential energy is assumed to be zero at the ground state level,choose the incorrect statement.

When a hydrogen atom is raised from the ground state to the excited state,

Which of the transitions in a hydrogen atom emits a photon of the lowest frequency? ($n =$ quantum number)

The figure shows the energy levels $P, Q, R, S$ and $G$ of an atom,where $G$ is the ground state. $A$ red line in the emission spectrum of the atom is obtained by an energy level transition from $Q$ to $S$. $A$ blue line can be obtained by which of the following energy level transitions?