In 1874 Jackson published his first paper which dealt with organic selenium compounds.

There are some organic selenium compounds, such as selenoproteins.

Sodium selenite is a salt, a colourless solid, and the most common water-soluble selenium compound.

The compound reacts with electrophiles to produce the selenium compounds.

The +1 state is found in some selenium compounds, such as selenium(I) chloride.

Some selenium compounds are very toxic and harmful to things that live in water.

It is used to make other selenium compounds.

It is the most toxic selenium compound with an exposure limit of 0.05 ppm over an 8 hour period.

SeCl is used in the synthesis of other selenium compounds.

Selenium dioxide can dissolve in water to make toxic selenium compounds.