This chemical is harmful.

This chemical is harmful and has a negative impact on the environment.

Chemotransmitters play an important role in the transmission of information between nerve cells.

He is majoring in chemistry at university.

What is this material made of?

He is an expert in chemistry.

The air in this area is greatly affected by pollutants emitted from factories.

The existence of dark matter has not yet been fully proven.

Antibiotics don't work for colds, so please don't take them unnecessarily.

It is said that antimatter has properties opposite to those of matter.