What change occurs in atoms as a result of ionizing radiation?

Ionizing radiation is characterized by its ability to remove tightly bound electrons from atoms, subsequently creating ions. This process involves the transfer of energy to the atoms, which can result in them becoming charged particles—ions. Ionization leads to changes in the structure of the atom, as the balance between the number of protons and electrons is disrupted. This can lead to chemical reactions and biological effects, impacting cellular regulation and potentially causing damage to tissues, which is particularly relevant in fields like oncology and radiology.

The other options do not accurately capture the effect of ionizing radiation. While solidification and ionic bonding can occur under specific conditions, they do not directly relate to the concept of ionizing radiation itself. Similarly, while ionizing radiation can lead to the formation of new chemical elements through nuclear reactions, this is not a direct result of the ionization of atoms in the same context as the question implies. Thus, the primary change that occurs due to ionizing radiation is indeed the ionization of atoms.