The nature of the sun's spectrum is

The solar spectrum is an example of

When light emitted by a white hot solid is passed through a sodium flame,the spectrum of the emergent light will show

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 $, eV$)?

$A$ photon collides with a stationary hydrogen atom in the ground state inelastically. The energy of the colliding photon is $10.2 \ eV$. After a time interval of the order of a microsecond,another photon collides with the same hydrogen atom inelastically with an energy of $15 \ eV$. What will be observed by the detector?

The emission spectrum of $CO_2$ gas is: