Physics · Nuclear Physics

This option is correct. Isotopes are forms of elements that have the same number of protons but different numbers of neutrons. Certain isotopes are radioactive and emit gamma rays. In medical imaging, radioactive isotopes are used to observe the radiations concentrated in organs, making them ideal for gamma ray cameras.

This option is incorrect. Atoms themselves do not emit gamma radiation in the context of medical imaging. While atoms may be involved in the composition of radiopharmaceuticals, it is the isotopes of specific elements that emit gamma radiation for diagnostic purposes.

This option is correct. Isotopes are forms of elements that have the same number of protons but different numbers of neutrons. Certain isotopes are radioactive and emit gamma rays. In medical imaging, radioactive isotopes are used to observe the radiations concentrated in organs, making them ideal for gamma ray cameras.

This option is incorrect. Nucleons refer to the particles (protons and neutrons) that make up the nucleus of an atom. While they are involved in the behavior of isotopes, they do not directly emit gamma radiation in a form useful for imaging. The emission of gamma rays is a property of the isotopes.

This option is incorrect. Neutrons are neutral subatomic particles that do not directly emit gamma rays. They play a role in nuclear reactions (such as in a reactor), but gamma rays are typically emitted by radioactive isotopes rather than neutrons.