It's difficult to decipher this chemical equation.

Understanding chemical equations is difficult.

We are growing vegetables without using chemical fertilizers.

Oxygen, which is one of the chemical elements, is necessary for us to breathe.

Understanding chemical equilibrium is very important in understanding chemical reactions.

This substance undergoes a chemical change when heat is applied.

In this experiment, you can observe a chemical reaction.

Reducing greenhouse gas emissions is important for environmental protection.

The use of weapons of mass destruction is prohibited by international law.

The government declared a state of emergency to prevent the spread of the new coronavirus.