The phosphorus center is the reactive site of the chemical.

Chemical filtration will cease when all reactive sites within the flow pathway through aquifer soil have reacted.

However, since molecules have shapes and the reactive site may be in a very small part/portion of the molecule, collisions must happen at this particular site.

Its aromaticity makes it relatively stable, although as a heterocycle, it has reactive sites which allow for functionalization.

Ground state conformations dictate the exposed face of the reactive site of the macrocycle, thus both local and distant stereocontrol elements must be considered.

Atmospheric gases do not generally provide such reactive sites for dye absorption.

In this process, the strongly coordinating methyl group transfers to the boron to expose a reactive site on zirconium.

In general, radicals attack the closest reactive site the most readily.

There also is the possibility to have more than two reactive sites on a monomer: In this case branched polymers are produced.

Between 1-5% of copolymerized 2-vinylpyridine provide the reactive sites for dyes.