The World of Metals and Non-metals

Overview

Materials can be grouped as metals and non-metals based on their properties. This chapter compares their appearance, behaviour and common uses.

Key concepts

• Metals are usually shiny, hard, malleable and ductile.
• Metals are good conductors of heat and electricity.
• Non-metals are mostly dull, brittle and poor conductors.
• Metals are sonorous (make a ringing sound).
• Exceptions exist, such as graphite (a non-metal that conducts).

Important terms / formulae

• Malleable: can be beaten into thin sheets.
• Ductile: can be drawn into wires.
• Lustre: the shine on a metal surface.
• Sonorous: produces a ringing sound when struck.

Solved example or key process

Test a sample by tapping it: a ringing sound and shiny surface suggest a metal. Try bending it; if it bends without breaking it is malleable. A piece that crumbles and looks dull is likely a non-metal.

Important questions

1. List four physical properties of metals.
2. Why are electrical wires made of copper?
3. Give two uses each of metals and non-metals.
4. Name one non-metal that conducts electricity.

Quick revision

Metals are shiny, malleable, ductile, sonorous and conduct heat and electricity. Non-metals are usually dull, brittle and poor conductors. A few exceptions break these rules.