George de Hevesy developed the tracer principle in which year?

George de Hevesy developed the tracer principle in which year?

• A. 1910
• B. 1923
• C. 1931
• D. 1940

Answer: (B)

Using a marked atom as a tiny signpost to follow where a substance goes and what it does inside a system is the idea being tested. George de Hevesy introduced this tracer principle in 1923, showing that radioactive isotopes could label elements and be tracked through chemical reactions or biological processes without altering the chemistry. This approach lets researchers map pathways, measure distribution, and study reaction mechanisms with minimal disturbance to the system. The year marks the first explicit demonstration of labeling elements with isotopes to trace their journey, laying the groundwork for radiochemistry and medical diagnostics. Later work refined and extended the method, but 1923 is the date closely associated with the tracer principle’s formal introduction.

Using a marked atom as a tiny signpost to follow where a substance goes and what it does inside a system is the idea being tested. George de Hevesy introduced this tracer principle in 1923, showing that radioactive isotopes could label elements and be tracked through chemical reactions or biological processes without altering the chemistry. This approach lets researchers map pathways, measure distribution, and study reaction mechanisms with minimal disturbance to the system. The year marks the first explicit demonstration of labeling elements with isotopes to trace their journey, laying the groundwork for radiochemistry and medical diagnostics. Later work refined and extended the method, but 1923 is the date closely associated with the tracer principle’s formal introduction.