What is black body radiation and photoelectric effect?

What is a black body?

What is black body and write Stefan's law.

What is threshold frequency in the photoelectric effect?

What is photoelectric emission?

Explain why wave theory can't explain photoelectric effect.

What do you mean by photo electric effect? Calculate the energy of one mole of photons of radiations having wave length 200 nm.

What is Doppler effect?

What is mass of a body?