Topics Included • Introduction • Metals → Physical properties of metals → Chemical Properties of metals • Non-metals → Physical properties of non-metals → Chemical Properties of metals • Difference between metals and non-metals • Reaction with Acids • Reaction with Bases

1. MATERIALS
METALS AND NON -METALS
Class 8 | Science

4. There are 118 known elements
Elements
Metals Non-Metals Metalloids

5. MATERIALS
METALS AND NON -METALS
Class 8 | Science
Topic: Physical Properties

6. Most metals are solid at
room temperature except
mercury, which is liquid.
Exception
Non-metals may exist in
solid, liquid or gaseous
state.
Example
Physical Properties: Physical State

7. Most metals have high
melting and boiling points.
Non-metals generally have
comparatively low melting
and boiling points.
Physical Properties: Melting & Boiling Point
MeltingTemperature
= 3400O C
Exception
Caesium
MeltingTemperature
= 28O C
Sulphur
MeltingTemperature
= 119O C
Exception
Diamond
MeltingTemperature
= 3723O C
Example
Example

8. Most metals are very hard.
They can withstand high
pressure.
Non-metals are not hard.
They are brittle.
Physical Properties: Hardness
Exceptions
Sodium Sulphur
Soft non-metal
Exception
Diamond
Hardest known
substance
Example
Examples
Iron
Potassium
Chromium

9. Most of the metals are
shiny.
Non-metals have dull
appearance.
Physical Properties: Lustre
Exceptions
Sodium Sulphur
Exception
Iodine
Example
Example
Potassium

10. Most metals can be drawn
into thin wires and can be
beaten into thin sheets.
Non-metals cannot be
drawn into thin wires nor
can be beaten into thin
sheets.
Physical Properties: Ductility & Malleability
Example
So, non-metals are neither
ductile nor malleable.

11. Most metals produce a
ringing sound when they
strike with hard objects.
Non-metals produce a dull
sound when they strike
with hard objects.
Physical Properties: Sonorous
Examples

12. Most metals are good
conductors of heat and
electricity.
Non-metals are poor
conductors of heat and
electricity.
Physical Properties: Thermal & Electrical Conductivity
Examples Example

13. Summery: Physical Properties
Metals are generally solid, hard, Lustrous,
malleable, ductile, good conductors of heat
and electricity, sonorous and have high
melting and boiling points.
Most non-metals do not have such properties.

14. MATERIALS
METALS AND NON -METALS
Topic: Chemical Properties Class 8 | Science

15. Metals react with Oxygen to form Metal Oxides.
Chemical Properties: Reaction with Oxygen
Metal + Oxygen → Metal Oxide
2Mg + O2 → 2MgO
Magnesium Oxygen Magnesium Oxide
Metal Oxides are Basic in nature.

16. Non-metals react with Oxygen to form Non-metal Oxides.
Chemical Properties: Reaction with Oxygen
Non-metal + Oxygen → Non-metal Oxide
C + O2 → CO2
Carbon Oxygen Carbon dioxide
Non-metal Oxides are Acidic in nature.

17. Metals react with Water to form Metal Hydroxides
and release Hydrogen gas.
Chemical Properties: Reaction with Water
Metal + Water → Metal Hydroxide + Hydrogen
Mg + 2H2O → Mg(OH)2 + H2
Magnesium Water(hot) Magnesium Hydroxide Hydrogen
Metal Hydroxides are Alkaline in nature.

18. Non-metals do not react with Water.
Chemical Properties: Reaction with Water
Some highly reactive Non-metals are stored in water.
Phosphorous is always stored in Water.

19. Metals react with Acids to form Metal Salts
and release Hydrogen gas.
Chemical Properties: Reaction with Acids
Metal + Acid → Metal Salt + Hydrogen
Fe + 2HCl → FeCl2 + H2
Iron Hydrochloric Acid Iron Chloride Hydrogen

20. Non-metals generally do not react with
Acids.
Chemical Properties: Reaction with Acid
Some Non-metals like Sulphur and Phosphorus react
with hot, concentrated Sulphuric Acid and Nitric Acid
but do not release Hydrogen gas..

21. MATERIALS
METALS AND NON -METALS
Topic: Chemical Properties Class 8 | Science

22. Reactivity of metals
The tendency of element to react with other
substances to form compounds is known as
its reactivity.
K Na Ca Mg Al Zn Fe Cu
Hg Ag Au Pt

23. Cu + MgSO4 →
Copper Magnesium
Sulphate
No
Reaction
Copper is less reactive than Magnesium.

24. Mg + CuSO4 → MgSO4 + Cu
Magnesium Copper
Sulphate
Magnesium
Sulphate
Copper
Displacement Reaction

25. A mineral is a naturally occurring inorganic substance
found deep under the earth’s surface
Mineral
Ore
Non-Metals Metals

26. Metals exist in the Earth’s crust.
Highly reactive metals like sodium, potassium,
aluminium, zinc etc. occur in the form of
their compound like oxides, sulphides and
carbonates.
Sodium Carbonate
Lead Sulphide
ferrous oxide