What is transmutation in nuclear physics?

• A. The emission of gamma rays from a nucleus
• B. The conversion of an atom of one element to an atom of another element
• C. The splitting of a heavy nucleus into lighter nuclei
• D. The emission of an electron from a nucleus during beta decay

Answer: (B)

Transmutation is turning one element into another by changing the number of protons in the nucleus. The identity of an element is defined by its atomic number (the count of protons), so any process that changes that count changes the element itself. Emitting a gamma ray only releases energy and does not change the proton number, so it isn’t transmutation. Processes like beta decay or alpha decay alter the proton count and therefore convert one element into a different one, which is the essence of transmutation. The key idea is that a nucleus must change its proton count to become a different element, which is exactly what the option describing conversion from one element to another states.