This system is very complex.

My child attends a supplementary school every Saturday.

The pH of this liquid is 7.

Arsine is a colorless, odorless, and highly toxic gas.

Lithium hydride plays an important role in chemical reactions.

Hydrogen peroxide is often used for disinfecting wounds.

Tritium is one of the radioactive isotopes.

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

In chemistry class, I learned about alkanes.

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