Question

Metals are good conductors of heat because:

• A. They contain a large number of free electrons
• B. Their atoms are relatively apart
• C. Their atoms collide frequently
• D. They have a reflecting surface

Answer 1

The correct option is A

They contain a large number of free electrons

Explanation for Correct answer:

Option A They contain a large number of free electrons

• The metals are particularly good conductors of heat.
• Their particles are tightly packed together and also possess a large number of free electrons within them.
• When the metal is heated, the free electrons near the heat source are heated.
• This makes them move faster as they travel through the metal, and collide with other atoms and electrons.
• Thus the heat passes quickly through the metal.
• Hence, option (A) 'They contain a large number of free electrons ' is the correct answer.

Explanation for incorrect answers:

Option B Their atoms are relatively apart

• Metals are good conductors of heat because of the presence of a large number of free electrons.
• Hence option (B) ‘Their atoms are relatively apart’ is incorrect'.

Option C Their atoms collide frequently

• Metals are good conductors of heat because of the presence of a large number of free electrons.
• Hence option (C) ‘Their atoms collide frequently’ is incorrect'.

Option D They have a reflecting surface

• Metals are good conductors of heat because of the presence of a large number of free electrons.
• Hence option (D) ‘They have a reflecting surface’ is incorrect'.