The Japanese imperial family line is said to have the longest history in the world.

She often reads books on spirituality.

She is deeply devoted to the New Age spirituality.

He loves 'Narou-kei' novels and reads them every day.

Alkenes play a very important role in organic chemistry.

Lithium hydride plays an important role in chemical reactions.

Hydrogen peroxide is often used for disinfecting wounds.

Tritium is one of the radioactive isotopes.

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

The pH of this liquid is 7.