He thinks that war is a necessary evil.

Do you understand the necessity of this project?

That information is unnecessary.

That information is completely unnecessary.

Metallic bonds are formed by ions floating in a sea of electrons.

When he opened the door, a metallic sound echoed.

Alkali metals are very reactive chemically.

Transition metals play an important role in chemical reactions.

His son was born with the disease of imperforate anus.

He stood on the battlefield wearing Japanese chainmail armour.