Understanding chemical equilibrium is very important in understanding chemical reactions.

He is an excellent chemist who made many discoveries.

This reaction occurs through a chemical process.

He is an expert in petrochemistry.

The study of organic compounds is an important field in chemistry.

I have been to Keelung City in Taiwan.

Kazumoto is my best friend.

The hydroxyl group plays a very important role in organic chemistry.

Free radicals play an important role in chemical reactions.

The foundation stone of this building was laid 100 years ago.