Question

A photon collides with a stationary hydrogen atom is ground state inelastically. Energy the colliding photon is $10.2eV$. After atime interval of the order of micro second another photon collides with same hydrogen atom inelatically with an energy of $15eV$. What will be observed by the detector?

• A. $2$ photons of energy $10.2eV$
• B. $2$ Photons of energy $1.4eV$
• C. One photon of energy $10.2eV$ and an electron of energy $1.4eV$
• D. One photon of energy $10.2eV$ and another photon of energy $1.4eV$

Answer 1

Answer: (C)

One photon of energy $10.2eV$ and an electron of energy $1.4eV$

According to the question,

Due to $10.2eV$ photon one photon of energy $10.2eV$ will be detected.
Due to $15eV$ photon the electron will come out of the atom with energy $(15-13.6)=1.4eV$.