# How does gamma radiation ionise atoms?

I am having trouble understanding how gamma radiation can ionise atoms. I think it is due to a lack of understanding about how photons work. My basic understanding is that gamma radiation doesn't directly ionise atoms like alpha and beta particles by 'knocking' electrons out of their orbitals. Gamma radiation causes atoms to emit other particles which then cause ionisation.

But then I read about how photons can hit electrons and transfer energy. Does this mean the electron gets removed and the atom gets ionised?

1-photoelectric effect: a photon hits an electron in an atom and disappears giving to the electron all its energy ($$E=h\nu$$, where $$h$$ is a constant and $$\nu$$ the frequency of the radiation).