Class 8 Science Chapter 4 Notes- Material Metal And Non-Metal
In this post, we will discuss Class 8 Science Chapter 4 notes pdf Material: Metal And Non-Metal Notes. Class 8th science ch 4 notes help students in revision. In Material: Metal And Non-Metal notes class 8, we will learn about the Physical and Chemical Properties of Metals and Non-metals and the Uses of Non-metals. You can also download Material Metal And Non-Metal notes class 8 pdf for further study. NCERT notes for the Class 8 Science Chapter 4 are designed by our subject expert team.
In this Class 8th Science Ch 4 Notes pdf, we will learn about Material: Metal And Non-Metal Notes
Class 8 Science Chapter 4 notes Overview
We are familiar with a number of materials like iron, aluminium, copper, etc. On the basis of physical and chemical properties, these materials are distinct as metal and non-metal.
In this post, Class 8 Science Chapter 4 notes Material: Metal And Non-Metal, we will study the Physical and Chemical Properties of Metals and Non-metals and their uses.
Malleability:-The property of metals by which they can be beaten into thin sheets is called malleability.
Ductility:- The property of metal by which it can be drawn into wires is called ductility.
Sonorous:- metals produce ringing sounds, they are said to be sonorous.
Physical Properties of Metals
- Metals are hard to touch.
- Metals are lustrous i.e have shining surfaces.
- Metals are malleable and ductile.
- Metals are good conductors of heat and electricity i.e metal can pass current and heat.
- Metals are sonorous i.e produce a ringing sound when stuck on a hard surface
- Metals like sodium and potassium are soft and can be cut with a knife.
- Mercury is the only metal which is found in a liquid state at room temperature. These are exceptions.
- Examples of metals are iron, copper, aluminium, calcium, magnesium, etc.
Physical Properties of Non-metals
- Non-metals are soft and dull like coal and sulphur are examples of non-metal.
- Non-metals are brittle i.e break down into a powdery mass on tapping with a hammer.
- Non-metals are not sonorous.
- Non-metals are poor conductors of heat and electricity i.e metal cannot pass current and heat.
- Examples of non-metals are sulphur, carbon, oxygen, phosphorus, etc.
Chemical Properties of Metals and Non-metals
Let us see how metals and non-metals react with oxygen, water, acid, and base and the nature of their result. here we also discuss displacement reaction in metal.
Reaction with Oxygen
Both metal and Non-metal when burnt in oxygen form their oxide.
Metal:- 2Mg(Magnesium)+O2(Oxygen)→ 2MgO(magnesium Oxide)
Non-metal:- S(sulphur)+O2(Oxygen)→ SO2(sulphur Dioxide)
- Oxides Of Metals are basic in nature.
- Oxides of Non-metals are acidic in nature.
Reaction with Water (H2O)
Let us see how metals and non-metals react with water.
Some metals react with H2O to produce metal hydroxide and hydrogen gas.
2Na(Sodium)+H2O(Water)→ 2NaOH(Sodium Hydroxide)+H2(Hydrogen gas)
Sodium metal is very reactive. It reacts vigorously with oxygen and water. A lot of heat is generated in the reaction. It is, therefore, stored in kerosene.
Generally, non-metals do not react with water though they may be very reactive in air. Such non-metals are stored in water. For example, phosphorus is a very reactive non-metal. It catches fire if exposed to air. To prevent the contact of phosphorus with atmospheric oxygen, it is stored in water.
Reactions with Acids
Non-metals generally do not react with acids but metals react with acids and produce hydrogen gas that burns with a ‘pop’ sound. You must have noticed that copper does not react with dilute hydrochloric acid even on heating but it reacts with sulphuric acid.
Reactions with Bases
Metals react with sodium hydroxide to produce hydrogen gas. Reactions of non-metals with bases are complex.
A more reactive metal can replace a less reactive metal, but a less reactive one cannot replace a more reactive metal.
Copper Sulphate (CuSO4) + Zinc (Zn) (Blue)→ Zinc Sulphate (ZnSO4) + Copper (Cu)(Colourless) (Red)
Uses of Metals
- Metals are used in making machinery, automobiles, aeroplanes, trains, satellites, industrial gadgets, cooking utensils, water boilers, etc.
Uses of Non-metals
- Non-metal (oxygen) is essential for our life which all living beings inhale during breathing.
- Non-metals (nitrogen, phosphorus) are used in fertilisers to enhance the growth of plants.
- Non-metals (chlorine) are used in the water purification process.
- Non-metal is used in the purple-coloured solution which is applied on wounds as an antiseptic.
- Non-metals are used in crackers.
What we learn Class 8 Science Chapter 4 notes Material: Metal And Non-Metal
In Class 8th Science Ch 4 Notes pdf / Material: Metal And Non-Metal Notes
- Metals are lustrous whereas non-metals have no lustre.
- Generally, metals are malleable and ductile. Non-metals do not have these properties.
- Generally, metals are good conductors of heat and electricity but non-metals are poor conductors.
- On burning, metals react with oxygen to produce metal oxides which are basic in nature. Non-metals react with oxygen to produce non-metallic oxides which are acidic in nature.
- Some metals react with water to produce metal hydroxides and hydrogen gas. Generally, non-metals do not react with water.
- Metals react with acids and produce metal salts and hydrogen gas. Generally, non-metals do not react with acids.
- Some metals react with bases to produce hydrogen gas.
- More reactive metals displace less reactive metals from their compounds in aqueous solutions.
- Metals and non-metals are used widely in everyday life.
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