Question

Threshold frequency explain particle nature of electromagnetic waves

Answer 1

You know according to Maxwell light is an electromagnetic wave. Now to justify the photoelectric effect on the outer surface of objects there are millions of atoms and each consists electrons so we can also call it a pool of electrons. Now to excite the electrons and get them out of there shells the electromagnetic wave consists of charged photons which give enough energy to the electrons to bounce off.
Now electrons don't bounce off because of all light waves and that minimum frequency needed by the light to excite them is the threshold frequency.
All this time I described the particle nature of electrons. To know about the particle nature of Light and photons that's advance quantum stuff which I don't know rn.