Thulium is a rare element, mainly used in the manufacture of lasers.

Hafnium is a chemical element with atomic number 72.

Cerium is one of the rare earth elements.

Yttrium is one of the rare earth elements.

Rhodium is a type of precious metal, very rare and valuable.

Gallium is one of the elements on the periodic table.

Osmium is the densest element on Earth.

Francium is a radioactive alkali metal that is hardly present in nature.

Actinium is a radioactive chemical element with the symbol Ac and atomic number 89.

The beaver uses wood to build a dam in the river.