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.

My child attends a supplementary school every Saturday.

He understands the meaning of the proverb 'Teaching is half learning', which means that teaching leads to one's own learning.

This compound has a tetrahedral molecular geometry.

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

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

No chemical flavoring is used in this ramen at all.