He is suffering from combat stress reaction.

The concept of chemical equivalent is essential for understanding chemical reactions.

My company specializes in the manufacture of fine chemicals.

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

Stoichiometry is a method for calculating the amount of substances in a chemical reaction.

No chemical flavoring is used in this ramen at all.

When he had a problem due to his own actions, he remembered the phrase 'chickens come home to roost'.