Metal | SEE Physics Notes

Metals | SEE Physics Notes

Metal: The element which is the conductor of heat and electricity, and forms (+) ve ion by losing electrons.
Example: Al, Fe, Cu, etc.

Mineral:

Definition: The minerals are the impure form of metal compounds with more amount of impurities.
Examples: Clay, Cryolite, etc.
The extraction of metals from mineral is very difficult and costly. All mineral are ore but not ores.

Ores:

Definition: The ores are a pure compound of the metal with less amount of impurities.
Examples: Siderite, Haematite, etc.
The extraction of metals from ores are economical and easy. All the ores are mineral.

`Metallurgy:

Definition: The science of metal extraction from ores is called Metallurgy.

Metallurgical process:
a) Crushing.
b) Pulverization.
c) Concentration and roasting.
d) Smelting.
e) Electrical refining, etc.

Explanation:

  1. Crushing: The process in which metallic ores are crushed into small pieces is called crushing.
  2. Pulverization: The process in which crushed ores are changed into a fine powder is called Pulverization.
  3. Concentration and roasting:
    i) Calcination: Calcination is a process of conversion of metallic ores containing carbonates and hydroxide to their respective oxides by heating strongly below their melting point either in the absence of air or in a limited supply of oxygen.
    ii) Roasting: The process of conversion of calcinated ores into metallic oxides by heating below their melting point excess of air.
  4. Smelting: The process of conservation of calcinated of roasted metallic oxides into metal by removing the oxygen by fusing it with carbon is called smelting.
  5. Electrical refining: The process of refining the crude metal for obtaining pure metals by the help of electricity is called electrical refining.

Some importance metal:

Iron:

Symbol: Fe
Atomic number: 26
Atomic weight: 56
Valency: 2, 3
Position in the periodic table: Period: 4, Group: VIII, d-block or transition element.
Colour: Grey white
Configuration:

ShellKLMN
No of electron28142

Specific gravity: 7.86
Melting point: 1500˚C
Boiling point: 2500˚C

Ores and minerals:

  • Haematite (Fe2O3)
  • Magnetite (Fe3O4)
  • Siderite (FeCO3)
  • Limonite ((Fe2O3.3H2O)
  • Iron pyrite (Fe2S2)

Properties of iron:

Physical properties:

  • Iron is a shiny grey coloured metal.
  • It melts at about 1500˚C and boils at about 2500˚
  • Its specific gravity is 7086.
  • Irons becomes non-magnetic above 770˚

Chemical properties:

  • Action with oxygen: When irons are heated in air, it forms ferrosoferric oxide.
    3Fe + 2O2 —-> Fe3O4
  • Action with steam: Iron reacts with steam at high temperature to form ferrosoferric oxide and hydrogen.
    3Fe + 4H2O —-> Fe3O4 + 4H2
  • Action with sulphur: Iron, on begins heated with sulphur, forms iron sulphide.
    Fe + S ——> FeS

 

Aluminium:

Symbol: Al
Atomic number: 13
Atomic weight: 27
Valency: 3
Position in the periodic table: Period: 3, Group: IIIA, P-block element.
Colour: Silver white
Configuration:

ShellKLM
No of electron283

Specific gravity: 7.86
Melting point: 660˚C
Boiling point: 1800˚C

Ores and Minerals:

  • Bauxite (Al2O3.2H2O)
  • Felspar K(AlSi3O8)
  • Cryolite (Na3Al F)

Properties of Aluminium:

Physical properties:

  • It is a silvery white and light metal.
  • It is highly malleable and ductile.
  • It is a good conductor of heat and electricity.
  • It’s melting point is 660°C and the Boiling point is 1800°C.
  • Its specific gravity is 2.7, etc.

Chemical properties:

  • Action with halogens: Aluminium reacts with halogens (Cl, B, I) to form halides.
    2Al + 3Cl2 → 2AlCl3
  • Action with nitrogen: When aluminium is strongly heated with nitrogen, aluminium nitride is formed.
    2Al + N3 → 2AIN (Aluminium nitride)

Uses of Aluminium:

  • Aluminium is a rusting resistant light metal. So, it is used to making a body of the aeroplane, cars, buses, etc.
  • Aluminium foil is used for wrapping foods, chocolates, photograph, and medicine, etc.
  • It is used in making different alloys.
  • Electirc cables are made from aluminium.
  • It is a good conductor of heat and electricity.
  • It is used for making coins.
  • Powdered aluminium is mixed in oil to form paint, etc.

Copper:

Symbol: Cu
Atomic number: 29
Atomic weight: 63.5
Valency: 1,2
Position in the periodic table: Period: 4, Group: IB, d-block element.
Colour: Brownish  red
Configuration:

ShellKLMN
No of electron28181

Specific gravity: 8.96
Melting point: 1083˚C
Boiling point: 2350˚C

Ores and minerals:

  • Copper pyrite or chalcopyrite (CuFeS2)
  • Copper glance or chalcocite (Cu2S)
  • Azurite [2Cu Co3.Cu(OH)2]
  • Malachite [Cu Co3.Cu(OH)2]
  • Cuprite (Cu2O)

Properties of Copper: 

Physical properties:

  • It is hard and brownish metal.
  • Its specific gravity is 8.93.
  • Its melting point is 1083˚C.
  • Its boiling point is 2350˚C.
  • It is a good conductor of heat and electricity.
  • It has a good degree of malleability and ductility, etc.

Chemical properties:

  • Action with halogen: Copper directly combines with halogens to form halides on heating.
    Cu + Cl2 → CuCl2
  • Action with Sulphur: When copper is heated with sulphur copper sulphide is formed.
    2C + S → Cu2S

Uses of Copper:

  • It is used to make household utensils such as cooking utensils.
  • It is used for making electric wires and other appliances.
  • It is used to make coins.
  • It is used for electroplating and electrotyping.
  • It is a good conductor of heat and electricity.
  • Coper slat is used as insecticides and germicides.
  • It is used for making alloys such as brass, bronze, etc.

Silver:

Symbol: Ag
Atomic number: 47
Atomic weight: 108
Valency: 1
Position in the periodic table: Period: 5, Group: 1B, d-block element.
Colour: Lustrous white
Configuration:

ShellKLMNO
No of electron2818181

Specific gravity: 10.5
Melting point: 960˚C
Boiling point: 1955˚C

Ores and minerals:

  • Argentite (Ag2S)
  • Silver copper glance (AgCu)2S
  • Horn silver (AgCl)
  • Ruby silver or pyrolite (3Ag2S.Sb2S3

Properties of Silver:

Physical properties:

  • It is a white shining metal.
  • Its melting point is 960˚C and boiling point is 1955˚C.
  • It is a very good conductor of heat and electricity.
  • It is highly malleable and ductile.
  • Its specific gravity is 10.5, etc.

Chemical properties of Silver:

  • Action with sulphur: Silver, on heating with sulphur produces silver sulphide.
    2Ag → Ag2S

Uses of Silver:

  • It is used for making utensils, coins and jewellery.
  • It is used for silver plating.
  • It is used in the manufacturing of silver nitrate which is very useful in laboratory reagent.
  • It is used for silvering mirrors and filling teeth.
  • Silver bromide (AgBr is used in photography, etc.

Gold:

Symbol: Au
Atomic number: 79
Atomic weight: 197.2
Valency: 1,3
Position in the periodic table: Period: 6, Group: 1B, d-block element.
Colour: Lustrous yellow
Configuration:

ShellKLMNOP
No of electron281832181

Specific gravity: 19.3
Melting point: 1063˚C
Boiling point: 2530˚C

Ores and Minerals:

  • Calverite (AuTe2)

Properties of Gold:

Physical properties:

  • It is a shining yellow metal.
  • It is a good conductor of heat and electricity.
  • It is highly malleable and ductile.
  • Its specific gravity is 19.3.
  • Its melting point is 1063˚C and boiling point is 2530˚C, etc.

Chemical properties of Gold:

  • Action with halogens: Gold on being heated with halogen forms halides.
    2Au +3Cl → 2AuCl3

Uses of Gold:

  • It is used for making jewellery, statues, etc.
  • It is used for making coins and medals.
  • It is used for filling teeth.
  • Compound of gold is used in photography and medicines.
  • It is used for gold plating, etc.

 

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