What are free radicals?
An atom or a group of atoms that has at least one unpaired electron and is therefore highly reactive and unstable, so such free radicals are likely to take part in chemical reactions which play an important role in atmospheric chemistry, combustion, polymerisation, plasma chemistry, biochemistry and many other chemical processes, including human physiology.
For example nitric oxide and super oxide regulate many biological processes, such as controlling vascular tone. “Radical” and “free radical” are frequently used interchangeably, however a radical may be trapped within a solvent cage or be otherwise bound. In 1900, the first organic free radical identified was triphenylmethyl radical, by Moses Gomberg at the University of Michigan.
