Cadmium is a harmful metal for the human body.

This chemical is harmful.

This chemical is harmful and has a negative impact on the environment.

The structure of the human body is very complex.

This metal is very hard.

He decided to become a subject of the human experiment for the new drug.

Transition metals play an important role in chemical reactions.

When he opened the door, a metallic sound echoed.

Alkali metals are very reactive chemically.

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