Materials Metals and Non Metals Class 8 Notes Physical Science Chapter 6

AP 8th Class Physical Science Notes Chapter 6 Materials Metals and Non Metals

→ 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.

Materials Metals and Non Metals Class 8 Notes Physical Science Chapter 6

→ Displacement reaction The reaction in which a more reactive element displaces a less reactive element from its compound in aqueous solution.

→ Ductility : The property of metal 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.

Materials Metals and Non Metals Class 8 Notes Physical Science Chapter 6

→ 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 are called Non-metals.

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

→ Lustrous : The materials which show brightness on surface and reflect the light are called lustrous.

Materials Metals and Non Metals Class 8 Notes Physical Science Chapter 6

→ Metals are lustrous whereas non-metals have no lustre.

→ The material which show brightness on surface and reflect the light are called lustrous and which do not shine are called non-lustrous material.

→ we Gerally, metals are malleable and ductile. Non-metals do not have these properties.
I The property of materials by which they can be beaten into thin sheets is called malleability.

→ The property of drawing materials to make fine wires is called ductility.

→ Generally, metals are good conductors of heat and electricity but non-metals are poor conductors.

→ The ability of materials to produce a particular sound when it is dropped on the hard surface is called sonorous.

Materials Metals and Non Metals Class 8 Notes Physical Science Chapter 6

→ Metals often possess all of the following properties. They are lustrous, hard, malleable, ductile, good conductors of heat and electricity and sonorous.

Eg. Iron, Zinc, Copper, Aluminium, Magnesium etc.

→ 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, nonmetals do not react with acids.

Materials Metals and Non Metals Class 8 Notes Physical Science Chapter 6

→ Some metals react with bases to produce hydrogen gas

→ More reactive metals displace less reactive metals from their compounds in aqueous solution.

→ Metals and non-metals are used widely in everyday life.

8th Class Physical Science Notes

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