Chapter 4

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Physical Properties of Metals:

Metals are:

  • Hard to touch.

  • Lustrous i.e.freshly cut surfaces of metals have characteristic shining.

  • Malleable; the property of metals by which they can be beaten into thin sheets is called malleability.

  • Ductile; the property of metal by which it can be drawn into wires is called ductility.

  • Sonorous; metals produce ringing sound when struck on a hard surface.

  • Good conductors of heat and electricity.

Metals like sodium and potassium are soft and can be cut with a knife.

Mercury is the only metal which is found in the liquid state at room temperature.

Physical Properties Of Non-metals:

  • Non-metals are soft and dull(e.g.coal and sulphur)

  • Non-metals are generally brittle i.e.they break down into a powdery mass on tapping with a hammer.

  • They are not sonorous.

  • They are poor conductors of heat and electricity.

Chemical Properties of Metals and Non-metals:

Reaction with oxygen: Both metals and non-metals when burnt in oxygen form their oxides.Oxides of metals are basic in nature while that of non-metals are generally acidic in nature e.g.

(a) 2Mg(s) + O2 (g) ----> 2mgO (s)

(b) S +O2 ------> SO2

Reaction with Water: Some metals react with water to produce metal hydroxide and hydrogen gas. Generally, non-metals do not react with water.

2Na + 2H2O ------> 2NaOH +H2

Reaction with Acids: Metals react with dil. acids and produce metal salt and hydrogen gas. Generally,non-metals do not react with dil. acids.

Reaction with Bases: Metals react with bases to produce hydrogen gas.

Displacement Reaction: more reactive metals displace less reactive metals from their metal compounds in aqueous solutions.

Uses of Metals and Non-metals-

  • Metals are used in making machinery, automobiles, aeroplanes, trains, satellites, industrial gadgets, cooking utensils, water boilers etc.

  • Non-metals are also used in day-to-day life.

Some examples are:

1.Oxygen is essential for life.

2.nitrogen,phosphorus and potassium are used as fertilizers.

3.chlorine is used as a water purifier.

Atom: Atom is the smallest particle of matter which cannot be divided further by any physical means. Atoms are the basic units from which molecules and ions are formed.

Conductor: Substances which allow heat/electricity to pass through them are called conductors of heat/electricity.

Displacement Reaction: More reactive metals displace less reactive metals from their compounds in aqueous solutions.

Ductility: The property of metals by which they can be drawn into wires is called ductility.

Elements: Substances whose molecules contain only one type of atoms are known as elements.

Hardness: Metals are hard, on the other hand, non-metals are generally brittle.

Malleability: The property of metals by which they can be beaten into thin sheets is called malleability.

Metals: The materials which are generally hard,lustrous,malleable,ductile, sonorous and good conductors of heat and electricity are called metals.

Metalloids: Elements which possess characters of both metals and non-metals are called metalloids.

Non-metals: Materials which are soft,dull in appearance,brittle, not sonorous and poor conductors of heat and electricity are called non-metals.

Sonorous: Metals are called sonorous because they produce a specific ringing sound.



We hope given CBSE/MP Board Class 8th Science Chapter 4 "Metal and Non-Metals" will help you.

Written By- Megha Tripathi