He is majoring in chemistry at university.

What is this material made of?

He is an expert in chemistry.

Sodium cyanide is widely used in the extraction of metals and the manufacture of electronic components.

Potassium cyanide is a very dangerous chemical.

This lake is known as a dangerous body of water.

This toothpaste contains fluoride.

We will use cyanide in this chemical experiment.

Please use the emergency stairs in case of a fire.

Due to the earthquake, the city declared a state of emergency.