NCERT Solutions Class 10th Science Chapter – 3 Metals and Non-metals Notes

June 2, 2022

NCERT Solutions Class 10th Science Chapter – 3 Metals and Non-metals

Textbook	NCERT
Class	10^th
Subject	Science
Chapter	3^rd
Chapter Name	Metals and Non-metals
Category	Class 10th Science
Medium	English
Source	Last Doubt

NCERT Solutions Class 10th Science Chapter – 3 Metals and Non-metals Notes What are the example of metal and non metal?, What are the 17 non-metals?, Which are the 11 non-metals?, What is called metal?, What is metal explain?, What are the main types of metals?, What are 5 uses of metals?, What are metal elements?, Is carbon a metal?, What are 22 nonmetals?, Is A Diamond a metal?, What are the 3 types of metals?, Is coal a metal?, Why are metals called?, How metal is made?, Why is metal important?, Which group is metal?, What is the symbol of metal? and What is metal and example? etc.

NCERT Solutions Class 10th Science Chapter – 3 Metals and Non-metals

Chapter – 3

Metals and Non-metals

Notes

1. Metal

Properties of Metal

• Solid
• Ductile
• Malleable
• Lusturous
• Sonorous
• Good conductor

Reaction with

• Air
• Water
• Acids
• Compounds of other metals
• Reactivity series

2. Non-Metal

Properties of Non-Metal

• Solids, Liquids or Gases
• Brittle
• Bad Conductor
• Non-Malleable
• non-Lustrous
• Non-Sonorous

Reaction with

Air

3. Alloys

Importance and Uses –

Prevent corrosion
Changed resistivity
changed melting point

Some alloys are Steel, Stainless steel, brass, bronze, solder and amalgam etc.

4. Metallurgy

Ore Enrichment
↓
Conversion of ore into Metal oxide: Roasting/Calcination
↓
Conversion of Metal oxide into metal:
↓
Heating Using Coke
↓
More reactive metal
↓
Electrolytic reduction
↓
Refining of Metals

5. Ionic Compounds

Formation by electron transfer from metal to non-metal.

Physical properties

• Solid state, brittle
• High melting point
• Soluble in water, insoluble in organic solvents
• Good conductor in aqueous solution and in molten state

6. Corrosion

Prevention of Rusting/Corrosion by galvanization, painting and anodizing etc.

(1) Rusting of Iron – Air and moisture are required to form rust (hydrated oxide of iron) Fe₂O₃. xH₂O.

(2) Silver – Reacts with H₂S to form black Ag₂S.

(3) Copper – Reacts with Moisture and CO₂ to Form green basic CUCO₃, Cu(OH)₂.

Metals and Non Metals

Metal

• About 118 elements are known till date. There are more than 90 metals, 22 non metals and few metalloids.

• Sodium (Na), Potassioum (K), Calcium (Ca), Magnesium (Mg), Iron (Fe), Aluminium (AI) are some metals.

Metals around us

Part of machines and defense equipments
Making bridges, buildings, railway tracks
Utensils and coins
Jewellery and Ornaments
Manufacturing of trains, cars, ships, aeroplanes

Non-Metal

Oxygen (O), Nitrogen (N), Hydrogen (H), Sulphur(S), Phosphorus (P), Fluorine (F), Bromine (Br) are a few non metals.

Non-Meatal arounds us

Carbon – as fuel, in nutrients, electrodes and jewellery.
Hydrogen – in hydrocarbons, making of fertillzers and vegetable ghee, as fuel.
Oxygen – in respiration, in fuel combustion.
Nitrogen – in preventing rancidity, in tyres and making of acids, fertillizers and explosives.

Different between Metal and Non-Metal

Metals	Non-Metals
1. Physical properties Solid at room temperature except mercury	1. Exist in all the three states, bromine, chlorine-gas, iodine-solid liquid
2. Ductile and malleable	2. Non-ductile and non-malleable
3. Sonorous and lustruous	3. Non-sonorous and non-lustruous except iodine and graphite
4. Generally have high melting, point, cesium and gallium have low melting point.	4. Have low melting, except diamond.
5. Generally good conductors of heat and electricity, except lead and mercury.	5. Poor conductors, except graphite.
6. Have high density, but sodium and potassium have low density.	6. Have low density.
7. Chemical properties Metal oxides can be basic or amphoteric in nature.	7. Oxides of non-metals are generally acidic in nature.
8. Many, metals displace hydrogen from dilute acids and release hydrogen gas.	8. Non metals cannot displace hydrogen from dilute acids.
9. Metal oxides are ionic in nature.	9. Non metal oxides are covalent in nature.

Chemical Properties of Metals –

1. Reaction with air
2. Reaction with water
3. Reaction with dilute acids
4. Reaction with other metal compounds
5. Reaction between metals and non-metals

1. Reaction with air

Metals can either burn, react or don’t react with air

Metal + Oxygen → Metal oxide

Example –

(i) 2Na + 0₂ → Na₂O
(ii) 2Mg + 0₂ → MgO
(iii) 2Cu + 0₂ → CuO (black)
(iv) 3Fe + 20₂ → Fe₃0₄

Some metals like Na and K are kept immersed in kerosene as they react vigorously with air.

Metals like Mg, AI, Zn and Pb react slowly with air and form a protective layer.

Magnesium can burn in air but combine with oxygen to form oxide. Fe and Cu does not burn in air but combine with oxygen to form their oxides.

Iron filings burn when sprinkled in the flame of burner.

Silver, platinum and gold show no reaction with air.

Amphoteric oxides – These are metal oxides which react with both acids as well bases.

Example: ZnO, Al₂O₃
(i) Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂0
(ii) Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O
Sodium aluminate = NaAlO₂

Anodizing of metals – In Anodizing, Aluminium is made anode and graphite as cathode, oxygen gas is released by the electrolysis of Sulphuric acid, which reacts with aluminium to form a thick protective oxide layer on the surface of metal.

2. Reaction with water

Metals react with water differently and Not all metals react with water.

Example –

(i) 2K + 2H₂0 → 2KOH + H₂
(ii) Ca + 2H₂O → Ca(OH)₂ + H₂
(iii) Mg + 2H₂0 → Mg(OH)₂ + H₂

Three Condition of Water form react with metal

Metal React with cold water
Example: Na, K, Ca
Metal React only with steam
Example: Fe, Al
Metal React with hot water
Example: Mg

• In case, of Ca and Mg, the metal starts floating due to bubbles of hydrogen gas sticking to its surface.

Example –

(i) 2Al + 3H₂O → Al₂O₃ + 3H₂
(ii) 3Fe + 4H₂O → Fe₃O₄+ 4H₂

3. Reaction with dilute acids

(i) Most metals react with dilute HCl and dilute H₂SO₄, to form salt and hydrogen gas.

Metal + dilute acid → salt + hydrogen gas

Example –

(a) Mg + 2HCl → MgCl₂ + H₂
(b) Al + 6HCl → 2AlCl₃ + 3H₂
(c) Zn + H₂SO₄ → ZnSO₄ + H₂

Important thing – Copper(Cu), Mercury(Hg) and Silver(Ag) don’t react with dilute acids.

(ii) With dilute nitric acid – As metals react with dilute nitric acid, hydrogen gas produced is oxidised to water. Mg and Mn are exceptions.
Mg + 2HNO₃ → Mg(NO₃)₂ + H₂

Aqua Regia – It is a mixture of concentrated HCl and concentrated HNO₃in a 3:1 ratio. It dissolves gold and platinum.

4. Reaction with other metal compounds

Metal A + Salt solution of metal B → Salt solution of Metal B + Metal A

More reactive metals can displace less reactive metals from their compounds in solution. This forms the basis of reactivity series of metals.

Reactivity series of metals – It is an arrangement of metals in decreasing order of their reactivity.

(i) K> Na > Ca > Mg > Al > Zn > Fe > Pb > H> Cu > Hg > Ag > Au → Decreasing reactivity

(ii) Copper being more reactive displace Silver

Example: Cu + 2AgNo₃ → Cu(NO₃)₂ + 2Ag

5. Reaction between metals and non-metals

NCERT Solutions Class 10th Science Chapter - 3 Metals and Non-metals Notes

Occurance of Metals

(1) Minerals – Compounds of metals present in earth’s crust can be termed as minerals.

(2) Ores – Mineral from which metal can be economically extracted is called an ore.

Example – sulphide ores, carbonate ores, oxide ores. Not all the minerals are ores.

Metals at the bottom of reactivity series like gold, platinum, silver, copper occur in free state. But copper and silver also occur in sulphide and oxide ores.

Metals of moderate reactivity (Zn, Fe, Pb) occur mainly as oxide, sulphide or carbonate ores. Metals of high reactivity (K, Na, Ca, Mg, AI) are found in combined states.

(3) Gangue – Ores are found mixed with earthly impurities like soil, sand, etc. known as gangue. The gangue is removed from the ore.

(4) Metallurgy – It is the step-wise process of obtaining metal from its ore.

These steps are

1. Enrichment of ore.
2. Obtaining metal from enriched ore.
3. Refining of impure metal to obtain pure metal.

Obtaining Metals low in the reactivity series

Extracting Metals in the middle of Activity series

Metals are easier to obtain from oxide ores, thus, sulphide and carbonate ores are converted into oxides.

Metal ore heated strongly in excess of air (Roasting)
Example: 2ZnS + 30₂ heat → 2ZnO + 2SO₂

Metal ore heated strongly in limited supply of air (Calcination)
Example: ZnCO₃ heat → ZnO + CO₂

Reduction of metal oxide –

1. Using coke – Coke as reducing agent.
Example – ZnO + C heat → Zn + CO

2. Using Displacement Reaction – highly reactive metal like Na, Ca and Al are used to displace metals of lower reactivity from their compounds.

Example –

(i) MnO₂ + 4Al heat → 3Mn + 2Al₂O₃ + heat
(ii) Fe₂O₃ + 2Al heat → 2Fe + Al₂O₃ + heat

In the above reaction Molten iron is formed and is used to join railway tracks. This is called thermit reaction.

Extracting Metals at the top of Activity Series

These metals Have more affinity for oxygen than carbon

These metals are obtained by electrolytic reduction. Sodium is obtained by electrolysis of its molten chloride

NaCI → Na⁺ + CI^–

As electricity is passed through the solution metal gets deposited at cathode and non-metal at anode.

(i) At cathode:
Na⁺+ e^– → Na

(ii) At anode:
2CI^– → CI₂ + 2e^–

Refining of Metals

Corrosion

Metals are attacked by substances in surroundings like moisture, acids, and moist air. Silver- it reacts with H₂S in air to form silver sulphide and articles become black.

Copper-reacts with moist carbon dioxide in air and gains a green coat of basic copper carbonate.

Iron-acquires a coating of a brown flaky substance called rust. Both air and moisture are necessary for rusting of iron.

Prevention of Corrosion

Alloys

These are homogeneous mixture of metals with metals or non-metals.
Adding small amount of carbon makes iron hard and strong.

Name of Alloy	Properties	Constituent metal/ Non-metal
1. Steel	Hard	Iron and carbon
2. Stainless steel	Hard, rust free	Iron, nickel and chromium
3. Brass	Low electrical conductivity than pure metal	Copper and zinc
4. Bronze	Hard and easily cast	Copper and tin
5. Solder	Low MP, used to weld wires	Lead and tin
6. Amalgam	Used by dentists	Mercury and any other metal