an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule
例句
用作名词 (n.)
In some cases free radicals can be detected. 在某些情况下可以测出自由基来。
A free radical is a molecular fragment having an unpaired electron. 自由基是一种具有未配对电子的分子碎体。