Radioactive isotopes (radioisotopes) of elements are commonly used in biological experiments as tracers to follow and detect molecules of interest. For example, photosynthetic intermediates produced during carbon dioxide conversion to sugars were detected by exposing algae to carbon dioxide containing a radioactive form of carbon. This radioactive carbon could be rapidly detected in molecules produced by the algae during carbon fixation and sugar production. Why can radioisotopes substitute for non-radioactive isotopes of elements in experiments?

Question

A.) because radioisotopes differ in electron number from non radioactive isotopes,they are more reactive and hence easier to trace
B.) because radioisotopes of an element differ only in the number of neutrons, they still behave the same way chemically
C.) because compounds containing radioisotopes are not acted upon by enzymes, the radioisotopes will not interfere with normal cellular processes
D.) because radioisotopes contain additional protons, they are heavier than non radioactive isotopes of an element and can hence be traced

Answer 1

Ans: B.) because radioisotopes of an element differ only in the number of neutrons, they still behave the same way chemically