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Properties of metals:

1. Solid state (Exception: Mercury and gallium) 

2. Typical lustre 

3. Malleability and ductility 

4. Hardness (Exception: Lithium, sodium and potassium) 

5. Good conductors of heat and electricity 

6. High melting and boiling points (On the other hand, the melting and boiling points of the metals sodium, potassium, mercury and galium are very low.) 

7. Sonorous and produce sound on striking a hard surface.

Properties or nonmetals:

1. Gaseous or solid state (Exception: Bromine in liquid state) 

2. Lack of any typical lustre (Exception: Iodine and Diamond) 

3. Brittleness in the solid state (Exception: Diamond is the hardest natural substance) 

4. Bad conductors of heat and electricity (Exception: Graphite) (Diamond is good conductor of heat) 

5. Low melting and boiling points.

1. Nonmetals may be solid or gaseous. 

2. Nonmetals lack lustre. They are not ductile and malleable. 

3. The melting and boiling points of nonmetals are low. 

4. Nonmetals are bad conductors of heat and electricity.

(1) Physical state: Under ordinary conditions, metals are generally solids. Exceptions: mercury and gallium are liquids. Under ordinary conditions, nonmetals may be solids or gases. Exception: bromine is in liquid state.

(2) Lustre: Metals usually have a high lustre (called metallic lustre). They can be polished to give a highly reflective surface. With the exceptions of gold and copper, metals usually have silvery grey colour. Nonmetals lack lustre, exceptions: graphite and iodine. Some nonmetals are colourless and others possess a variety of colours.

(3) Ductility and malleability: Metals are ductile and malleable. Nonmetals are not ductile and mallfeable.

(4) Conduction of heat and electricity: Metals are good conductors of heat and electricity. Nonmetals are bad conductors of heat and electricity. Exception: Graphite is a good conductor of electricity.

(5) Hardness: Metals are usually hard, but not brittle, exceptions: sodium, potassium, lead, zinc. Nonmetals are brittle in the solid state, exception: diamond.

(6) Melting and boiling points: The melting and boiling points of metals are high, exceptions: sodium, potassium, mercury, gallium. The melting and boiling points of nonmetals are low, exceptions: carbon, silicon.

A homogenous mixture of two or more metals or a metal and a nonmetal in a definite proportion is called an alloy. The physical properties of an alloy are different from those of its constituents. Alloys are corrosion resistant. Alloy decreases the intensity of corrosion of metals.

Examples: Brass is made from copper and zinc, 90 % Copper and 10 % tin are used to make an alloy called bronze, Stainless steel is made from 74% iron, 8 % carbon and 18 % chromium.

(1) The process of coating a thin layer of zinc on iron or steel is called galvanization.

(2) In this method corrosion of zinc occurs first because zinc is more electropositive than iron. After a few years zinc layer goes away and the iron layer gets exposed and starts rusting.

(3) In galvanization an iron object is dipped into molten zinc. A thin layer of zinc is formed all over the iron object. 

Examples: Shiny iron nails, pin, iron pipes.

i. Brass : Copper and Zinc :: Bronze : Copper and tin

ii. Tinning : Tin :: Galvanizing : Zinc

iii. Pressure cooker : Anodizing :: Silver plated spoons : Electro-plating

iv. The sulphides ores are strongly heated in air : Roasting :: The carbonates ores are strongly heated in a limited supply of air : Calcination.

v. Sulphide ores : Froth floatation method : Cassiterite ore : Magnetic separation method.

The substance  is an alloy Bronze.

Solder is an alloy of lead and tin.

B. Copper and zinc.

1. Fusible alloy 

2. Zincite (ZnS) 

3. Copper oxide (CuO)

(1) The electrons in the outermost shells of atoms of a metal are free to move throughout the metal.

(2) When a potential difference is applied between the ends of a metal wire, the net movement of the electrons in a particular direction, from a point at lower potential to a point at higher potential, constitutes an electric current. Hence, metals are good conductors of electricity.

1. The property due to which a substance can be drawn into a thin wire without cracking or breaking is called ductility. 

2. Metals are ductile. Thus, a metal can be drawn into a wire.

 In activity series of metal, iron occupies a higher position than hydrogen; while silver is placed below hydrogen; hence iron is more reactive than silver and is able to displace hydrogen from dilute sulphuric acid.

Fe + H₂SO₄ ⟶ FeSO₄ + H₂↑

(i) (a)

(b)

(ii) (a) Metals complete their octet by the loss of electrons whereas non-metals complete their octet by the gain of electrons. Metals generally contain 1 to 3 valence electrons in their outermost shell whereas non-metals contain 4 to 7 valence electrons in their outermost shell. 

(b) Metals form basic oxides whereas non-metals form acidic oxides. 

(c) Metals are reducing agents whereas non-metals act as oxidising agents. 

(d) Metals He generally good conductors of heat and electricity whereas non-metals are bad conductors of heat and electricity. 

(iii) (a) The minerals contain a low percentage of metal, while the ores contain a large percentage of the metal. 

(b) The metal cannot be extracted from mineral, on the other hand ores can be used for the extraction of metal. 

(c) All minerals are not ores, but all ores are minerals. 

(i) (a) Haematite (Fe₂O₃ ). 

(b) Bauxite (Al₂O₃ ). 

(ii) Reduction of the oxide is an important step in extraction of metal. In case of iron, Fe₂O₃ + 3CO ⟶ 2Fe + 3CO₂ Al₂O₃ cannot be easily reduced, hence it is subjected to electrolysis. Aluminium is collected at the cathode. 

(iii) Iron ore contains impurities of silica and sand. These are removed by magnetic separation. Bauxite and aluminium ore contains impurities of FeO and SiO₂ . Bauxite containing FeO is calcinated at high temperature when FeO is oxidised to Fe₂O₃ . Calcinated ore is then treated with NaOH when Al₂O₃ is converted into soluble NaAlO₂ .Fe₂O₃ can thus be filtered off. Bauxite containing SiO₂ is mixed with coke and heated to 1000°C in an atmosphere of N₂ . Silica is reduced to Si which volatilises at the temperature of reaction. Aluminium oxide is converted into AIN which is hydrolysed with water to obtain Al(OH)₃ . 

(iv) Carbon is major impurity present in iron.

Calcium, and magnesium are other two metals, which can be extracted by electrolytic reduction method. 

 (i) Zinc sulphide (ZnS). 

(ii) Zinc blende is oxidized to zinc oxide by roasting in presence of excess air, 

(iii) Reduction of zinc oxide. 

(iv) Immiscible. 

(v) Brass [7% of Cu, 30% of Zn].

(i) Zinc sulphide [ZnS]. 

(ii) Zinc blende is oxidised to zinc oxide by roasting in presence of excess air on reverberatory furance. 

(iii) Reduction of zinc oxide. 

(iv) Immiscible. 

(v) Brass

(1) Magnesium chloride (MgCl₂):

MgCl₂ → Mg²⁺ + 2Cl^–

At the cathode: Mg²⁺ + 2e^– → Mg

At the anode: 2Cl^– → Cl₂ + 2e^–

(2) Calcium chloride (CaCl₂):

At the cathode: Ca²⁺ + 2e^– → Ca

At the anode: 2Cl^– → Cl₂ + 2e^–

1. Aluminium 

2. Platinum

Coke (C) is a better reducing agent for the reduction of ZnO. Because, when we use coke, the reduction can be easily carried out at 673 K. Thus Carbon (Coke) reduces zinc oxide more easily than carbon monoxide (CO). From the Ellingham diagrams, it is quite clear that the reduction of zinc oxide is more favourable using coke ∆G for the formation of carbon monoxide from carbon is more negative).

• If the number of electrons in the outermost orbit of an atom of a metal is less, the metal is more reactive.
• Sodium has electronic configuration (2, 8, 1) and aluminium has electronic configuration (2, 8, 3). The number of electrons in the outermost orbit of sodium and aluminium atoms are 1 and 3, respectively. Hence, sodium is more reactive than aluminium.

1. Calcium reacts with water less vigorously hence the heat evolved is not sufficient for hydrogen to catch fire. 

2. Instead, calcium floats on water because the bubbles of hydrogen gas formed stick to the surface of the metal.

The reactivity of metal decreases in the following order:

Na > Mg > Ca > Zn > Fe > Cu.

Cryolite and fluorspar are used for dissolving Al₂O₃. it is used in molten state.

i. The reaction of iron oxide with aluminium is known as thermit reaction.

ii. The process of coating a thin layer of zinc on iron is known as galvanising.

iii. The metal that produces a sound on striking a hard surface is said to be sonorous.

iv. The process in which carbonate ores are changed into oxides by heating strongly in limited air is known as calcination.

v. Ionic compounds are insoluble in solvents like kerosene and petrol.

vi. Electrolys is method is used to obtain pure metals from impure metals.

vii. Corrosion can be prevented by putting a layer of non-corrosionable metal on corrosionable metal.

“By dissolving aluminium oxide in cryolite a conducting solution is produced. The graphite anodes are periodically replaced during electrolysis process of fused alumina. At cathode : 2Al³⁺ + 6e^– → 2Al.