Chemistry
Using Isotopic Labeling to Trace Reaction Mechanisms
Quick fact
Using isotopic labeling, chemists can determine whether a reaction proceeds through a concerted or stepwise mechanism. For example, replacing a specific carbon with carbon-13 makes it detectable in the product by mass spectrometry, revealing which bonds were formed or broken.
Why this is interesting
How can chemists identify which carbon atom in a reactant ends up attached to which atom in the product? The answer lies in using atoms that have different masses but nearly identical chemical behaviour.