Illustrated Glossary of Organic Chemistry

Abstraction: Removal of an atom or group from a molecule by a radical. Hydrogen atom abstraction is often confused with deprotonation, which is the removal of a hydrogen atom (i.e., a proton) by a base in an acid-base (proton transfer) reaction.

Hydrogen atom abstraction by bromine radical is the second step in the mechanism for free radical bromination of methylcyclohexane. This is not a deprotonation because bromine radical provides only one electron to form the new hydrogen-bromine bond. In a deprotonation, the bromine would provide both electrons for the new hydrogen-bromine bond.