Gr.7 Chemistry Quiz

_________________ is used as a roofing material.

• copper

• silver

• iron

A chemical reaction in which oxygen combines with a substance is called _______________.

• reduction

• Oxidation

• metabolism

The chemical name for rust is ___________ __________.

• carbon dioxide

• hydrated iron oxide

• iron hydroxide

The steel used for girders is coated in zinc in a process called………..

• galvanizing

• chromium plating

• electroplating

The surface of bronze develops a thin green film over a long time……..

• verdigris

• patina

• chromium

3. Steel can also be protected by covering the surface with……………

• chromium

• tin

• mercury

When aluminium or zinc is exposed to the air, the metal on its surface reacts with………… .

• nitrogen

• oxygen

• carbon

A black coating or tarnished forms on the surface of……………exposing on the air.

• silver

• copper

• zinc

The tarnish can be removed by……………… .

• coating

• polishing

• rusting

Nickel and ……………..to make the metal alloy called stainless steel.

• chromium

• auminium

• copper