Question

Work function of aluminium is 4.2 ev. If two photons each of energy 2.5ev are incident on its surface will the emission of photoelectrons take place?

Answer 1

Answer:

Explanation:

Work function of aluminium = 4.2 eV (Given)

Number of photons = 2 (Given)

Energy of each photon = 3.5eV (Given)

Electron emission refers to the process of an electron escaping from a metal surface. Every possible atom has a positively charged nuclear part and many negatively charged electrons around it.

The energy of two photons can not be added at the moment, when the photons collide with electron. Thus, all the energy of photon will be dissipated or wasted as the energy generated is not sufficient to knock it out.  

Thus,if two photons, each of energy 3.5 eV strike an electron of aluminium, then emission of electrons is not possible.