Question

Name one metal in each part fitting the given description:

A metal that reacts with oxygen without burning.

• A. aluminium
• B. chromium
• C. iron
• D. None of the above

Answer 1

Answer: (A), (C)

The correct options are
A aluminium
C iron

Metals react with oxygen to form metal oxides which are basic in nature and turn red litmus blue. The vigour reaction of oxygen depends upon the chemical reactivity of the metal. Potassium, sodium, lithium, calcium and magnesium react with oxygen and burn in air. Metals in the reactivity series from aluminium to copper react with oxygen in the air to form the metal oxide.

Aluminium is the fastest and copper is the slowest of the six.Aluminium reacts quickly to form a surface layer of aluminium oxide. Iron reacts slowly at room temperature but quickly if it is heated.