Within atoms and molecules, electrons are normally found in pairs. However, in some cases only a single unpaired electron will occupy an orbital plane. These substances are referred to as free radicals. They are often unstable as they have a strong tendency to lose or pick up an extra electron to achieve the "more natural" paired state. Despite having an unpaired electron free radicals do not necessarily have a negative charge and some can actually be relatively stable. However, more often than not substances containing radical electrons are usually highly chemically reactive. Free radicals play a key role in combustion and many other important chemical processes. These independent electrons serve an important role and are a reminder of the "power of one."