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?

As the quantum number $n$ increases,the difference in energy between consecutive energy levels

If the binding energy of the electron in a hydrogen atom is $13.6 \ eV$,then the energy required to remove the electron from the first excited state of $Li^{2+}$ is: (in $eV$)

The recoil speed of a hydrogen atom after it emits a photon in going from $n = 5$ state to $n = 1$ state will be ..... $m/s$.

An electron collides with a fixed hydrogen atom in its ground state. The hydrogen atom gets excited and the colliding electron loses all its kinetic energy. Consequently,the hydrogen atom may emit a photon corresponding to the largest wavelength of the Balmer series. The minimum kinetic energy $(K.E.)$ of the colliding electron will be.....$eV$.

Which of the following transitions in hydrogen atoms emit photons of highest frequency?