Scientists and engineers say the reactive form of mercury is easier to remove from power plants, which may address some local concerns about hot spots.

In 1910, Lord Rayleigh found out that when a spark was passed through nitrogen, it made a reactive form of nitrogen.

There are four ways to convert N (atmospheric nitrogen gas) into more chemically reactive forms:

Hypochlorite tends to decompose into chloride and a highly reactive form of oxygen:

Although it is the most abundant element in our atmosphere, atmospheric nitrogen cannot be used until it is "fixed" into a reactive form.

Ozone - a highly reactive form of oxygen - is used in some purification plants.

Human activities now convert more nitrogen from the atmosphere into reactive forms than all of the Earth's terrestrial processes combined.

Paradoxically, it is also thermodynamically the least stable, as well as the most volatile and reactive form.

The nutrients act as antioxidants, which block the damaging effects of highly reactive forms of oxygen on compounds in the body.

Further, moderation may take two different forms: reactive or proactive.