A free radical is an atom or molecule that has an unpaired one of these
These latter compounds are said 
to be 'metastable,' meaning they will decompose or react if given enough time,... [DOC] [TLE] free radical chemistry [PAR] One of the most common and useful reaction for making polymers is free radical 
... What is special about these molecules is that they have an uncanny ability to 
fall ... Molecules like this, with unpaired electrons are called free radicals.