I think I understand the impact that an alpha particle can have on living tissue. Not having electrons in it valence it would be very reactive - stripping electrons from atoms or molecules it bumps into (assuming it made its way in a biotic host). But how does a beta particle ionize an atom or molecule? If the target atom/molecule had a full valence wouldn't the beta particle just get deflected? And, if it were to join a full valence wouldn't it just knock another electron out, leaving the initial target atom/molecule unchanged? Regarding gamma rays, how exactly do they interact with an atom/molecule? How does a photon ionize an atom/molecule? Thanks again.