In matter, fast charged particles interact with electron shells and atomic nuclei. As a result of interaction with a fast charged particle, the electron receives additional Energy and goes to one of the energy levels far from the nucleus or leaves the atom completely. In the first case, excitation occurs, in the second, ionization of the atom.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.