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:
- Crushing: The process in which metallic ores are crushed into small pieces is called crushing.
- Pulverization: The process in which crushed ores are changed into a fine powder is called Pulverization.
- 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. - 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.
- 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:
Shell | K | L | M | N |
---|---|---|---|---|
No of electron | 2 | 8 | 14 | 2 |
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:
Shell | K | L | M |
---|---|---|---|
No of electron | 2 | 8 | 3 |
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:
Shell | K | L | M | N |
---|---|---|---|---|
No of electron | 2 | 8 | 18 | 1 |
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:
Shell | K | L | M | N | O |
---|---|---|---|---|---|
No of electron | 2 | 8 | 18 | 18 | 1 |
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:
Shell | K | L | M | N | O | P |
---|---|---|---|---|---|---|
No of electron | 2 | 8 | 18 | 32 | 18 | 1 |
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.