Hydrogen sulphide is extremely toxic, and particularly at high concentrations, it is lethal to humans.

He was involved in the development of the hydrogen bomb.

He is dedicated to the study of immunochemistry.

Thermochemistry is a part of chemistry that deals with the reactions of heat and matter.

This chemical reaction is very dangerous.

This shirt is made of chemical fiber.

The use of chemical weapons is prohibited by international law.

I am majoring in biochemistry at university.

I am majoring in inorganic chemistry at university.

My major is chemical engineering.