Heat and electricity

The idea

Metals are good conductors of heat and electricity and have high melting points; silver and copper are the best conductors of heat, while lead and mercury are comparatively poor ones.

A spoon in a hot drink

One end of a metal spoon is dipped in a hot drink.

What happens at the other end of the spoon?

• It gets hot too
• It stays cold
• It turns to powder

Best and poorer conductors

Sort the four metals: best conductors of heat, or comparatively poor ones?

Good conductors

Metals are good conductors of heat and of electricity, and they have high melting points. Among them, silver and copper are the best conductors of heat. Lead and mercury are comparatively poor conductors.

Metals are good conductors of heat and electricity and have high melting points; silver and copper are the best conductors of heat, while lead and mercury are comparatively poor ones.

Notes

Metals conduct heat and electricity, have high melting points; silver and copper conduct heat best, lead and mercury comparatively poorly.

Check yourself

Metals are good conductors of ...

Which two are the best conductors of heat?

Compared with other metals, lead is a ... conductor of heat.

Metals have ... melting points.

• heat only, not electricity. The book says metals are good conductors of heat and electricity.
• heat and electricity — correct. Yes!
• electricity only, not heat. The book says metals are good conductors of heat and electricity.
• Lead and mercury. Lead and mercury are comparatively poor conductors of heat.
• Gold and lead. The book names silver and copper as the best conductors of heat.
• Silver and copper — correct. Yes!
• comparatively poor — correct. Yes!
• very good. Silver and copper are the best conductors of heat; lead is comparatively poor.
• the best. Silver and copper are the best conductors of heat; lead is comparatively poor.
• low. The book says metals have high melting points.
• high — correct. Yes!
• no. Metals do have melting points; the book says they are high.