Final answer:
Gamma radiation is the type of high-frequency electromagnetic radiation emitted by the nuclei of some radioactive atoms, having the shortest wavelengths and highest energy content, which can penetrate materials deeply and pose risks to living tissues.
Step-by-step explanation:
The type of electromagnetic radiation with high frequency that is emitted by nuclei of some radioactive atoms is gamma radiation. Gamma rays are electromagnetic radiation with the shortest wavelengths, which are no longer than 0.01 nanometer. These rays have very high frequencies and, as a result, hold a significant amount of energy. They can be particularly harmful to living tissues because of their high energy content.
Gamma radiation is not only produced during certain types of radioactive decay processes but is also emitted by cosmological phenomena, such as the deaths of stars. Unlike alpha radiation and beta radiation, which consist of particles, gamma rays are pure energy and do not consist of particles, thereby distinguishing them in their unique ability to penetrate materials more deeply.