Who developed the tracer principle?

Who developed the tracer principle?

• A. George de Hevesy
• B. Ernest Lawrence
• C. Enrico Fermi
• D. Hal Anger

Answer: (A)

The tracer principle is the idea that a labeled form of an element, often a radioactive isotope, can be followed through a chemical or biological process without changing the system’s behavior. This allows you to see where a substance goes and how it’s transformed by detecting the label, rather than disturbing the process itself. George de Hevesy developed this approach, using radioactive isotopes to trace chemical pathways and reactions. His insight opened the door to radiochemical tracing in chemistry, biology, and later medical imaging. While the other figures made major contributions to related areas—such as producing isotopes with a cyclotron, advancing nuclear physics, or creating an imaging detector—they aren’t credited with developing the tracer principle itself.

The tracer principle is the idea that a labeled form of an element, often a radioactive isotope, can be followed through a chemical or biological process without changing the system’s behavior. This allows you to see where a substance goes and how it’s transformed by detecting the label, rather than disturbing the process itself. George de Hevesy developed this approach, using radioactive isotopes to trace chemical pathways and reactions. His insight opened the door to radiochemical tracing in chemistry, biology, and later medical imaging. While the other figures made major contributions to related areas—such as producing isotopes with a cyclotron, advancing nuclear physics, or creating an imaging detector—they aren’t credited with developing the tracer principle itself.