The band spectra (characteristic of molecular species) is due to emission of radiation from which state of matter?

The ionisation energy of an electron in the ground state of a helium atom is $24.6 eV$. The energy required to remove both electrons is: (in $eV$)

Match the appropriate pairs from List-$I$ and List-$II$:

List-$I$	List-$II$
$1$. Nitrogen molecules	$(A)$ Continuous spectrum
$2$. Incandescent solids	$(B)$ Absorption spectrum
$3$. Fraunhofer lines	$(C)$ Band spectrum
$4$. Electric arc between iron rods	$(D)$ Emission spectrum

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 number of completely filled shells for the element ${ }_{16} S ^{32}$ is

The collision of an electron with kinetic energy $5.5 eV$ and a hydrogen atom in its ground state can be described as