Metal | SEE Physics Notes

April 28, 2019

Table of Contents

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: