The solar spectrum is an example of

An electron of a stationary Hydrogen atom transitions from the fifth energy level to the ground level. The velocity that the atom acquires as a result of photon emission is ( $m=$ mass of the atom,$R=$ Rydberg's constant,$h=$ Planck's constant).

The energy required to remove one electron from a helium atom is $24.6 \, eV$. What is the energy required to remove both electrons from the helium atom (in $, eV$)?

$A$ stationary hydrogen atom emits a photon corresponding to the first line of the Lyman series. The recoil velocity of the atom is nearly (in $m/s$)

Which of the following spectra contains all frequencies from the high to the low frequency range?

An energy of $24.6\ eV$ is required to remove one of the electrons from a neutral helium atom. The energy (in $eV$) required to remove both the electrons from a neutral helium atom is