This is my first question.

Rare earth elements are essential materials for the manufacture of electronic devices.

An isotope refers to elements with the same atomic number but different numbers of neutrons.

Transition elements play an important role in chemical reactions.

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

The one-eyed goblin was dancing in the forest.

Radioactive elements are produced in nature and scientific experiments.

His long talk is just like 'a hundred days of sermonizing without a fart.'