Chapter – The World of Metals and Non-
Metals
Introduction
Matter around us is made up of a large variety of substances. These substances can
be classified broadly into metals and non-metals depending upon their physical and
chemical properties.
Definition: A metal is an element which is generally hard, lustrous, malleable,
ductile, sonorous, a good conductor of heat and electricity, and forms positive ions
by losing electrons.
Definition: A non-metal is an element which is generally soft (except diamond),
non-lustrous, brittle, poor conductor of heat and electricity, and forms negative ions
by gaining electrons.
Examples:
• Metals – Iron, Copper, Aluminium, Silver, Gold, Zinc, Sodium.
• Non-Metals – Oxygen, Sulphur, Carbon, Nitrogen, Chlorine.
Physical Properties of Metals
1. Lustre: Metals are shiny (metallic lustre). Example: Gold, silver.
2. Hardness: Most metals are hard (except sodium, potassium).
3. Malleability: Metals can be beaten into thin sheets. Example: Aluminium foil.
4. Ductility: Metals can be drawn into wires. Example: Copper wire.
5. Conduction: Good conductors of heat and electricity (Silver, Copper best).
6. Density & Strength: Generally high (iron, steel used in construction).
7. Melting/Boiling Points: Usually high (except low for sodium, potassium,
mercury).
8. Sonority: Metals produce ringing sound when struck.
□ Activity 1 – Testing Malleability of Metals
Materials: Small pieces of aluminium, copper, coal, sulphur, hammer.
Procedure: Hammer each sample.
Observation: Aluminium and copper spread into sheets; coal and sulphur break.
Conclusion: Metals are malleable; non-metals are brittle.
Metals
Introduction
Matter around us is made up of a large variety of substances. These substances can
be classified broadly into metals and non-metals depending upon their physical and
chemical properties.
Definition: A metal is an element which is generally hard, lustrous, malleable,
ductile, sonorous, a good conductor of heat and electricity, and forms positive ions
by losing electrons.
Definition: A non-metal is an element which is generally soft (except diamond),
non-lustrous, brittle, poor conductor of heat and electricity, and forms negative ions
by gaining electrons.
Examples:
• Metals – Iron, Copper, Aluminium, Silver, Gold, Zinc, Sodium.
• Non-Metals – Oxygen, Sulphur, Carbon, Nitrogen, Chlorine.
Physical Properties of Metals
1. Lustre: Metals are shiny (metallic lustre). Example: Gold, silver.
2. Hardness: Most metals are hard (except sodium, potassium).
3. Malleability: Metals can be beaten into thin sheets. Example: Aluminium foil.
4. Ductility: Metals can be drawn into wires. Example: Copper wire.
5. Conduction: Good conductors of heat and electricity (Silver, Copper best).
6. Density & Strength: Generally high (iron, steel used in construction).
7. Melting/Boiling Points: Usually high (except low for sodium, potassium,
mercury).
8. Sonority: Metals produce ringing sound when struck.
□ Activity 1 – Testing Malleability of Metals
Materials: Small pieces of aluminium, copper, coal, sulphur, hammer.
Procedure: Hammer each sample.
Observation: Aluminium and copper spread into sheets; coal and sulphur break.
Conclusion: Metals are malleable; non-metals are brittle.
