The spectrum of iodine gas under white light will be:

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 $eV$)

$A$ 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?

Band spectrum is produced by

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 will be:

What is the atomic number of gold?