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.
→ 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.
→ 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.
→ 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.
→ 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.
→ 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.