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Class X
CH-3 Metals and Non-metals
Syllabus of Metals and nonmetals: Properties of metals and non-metals, reactivity
series, formation, and properties of ionic compounds, basic metallurgical
processes, corrosion and its prevention.
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1. Malleability- Some metals can be beaten into thin sheets. This property of the metal is called malleability. Gold and silver are the most malleable metals.
2 Ductility- The ability of metals to be drawn into thin wires is called ductility.
3. Most ductile metal - Gold is the most ductile metal. Gold is used for jewelry because of their malleability and ductility that gold can be given different shapes according to our needs.
4. Cooper and Aluminium metals are used for making cooking vessels because these metals are good conductors of heat and have high melting points.
5. The best conductors of heat are silver and copper. Lead and mercury are comparatively poor conductors of heat.
6. The wires that carry current in our homes have a coating of polyvinylchloride (PVC) or a rubber-like material because these wires are bad conductors of electricity.
7. The metals that produce a sound on striking a hard surface are said to be sonorous. School bells are made of sonorous metals.
8. Examples of Non - Metals- Non-metals are carbon, sulfur, iodine, oxygen, hydrogen, etc. The non-metals are either solids or gases except bromine which is a liquid.
9. General physical properties of metals:
(i) All metals except mercury exist as solids at room temperature.Metals have high melting points but gallium and cesium have very low melting points. These two metals will melt if you keep them on your palm.
(ii) Metals are generally hard but alkali metals (lithium, sodium, potassium) are so soft that they can be cut with a knife. They have low densities and low melting points.
(iii) Metals are lustrous (Iodine is a non-metal but it is lustrous), malleable, and ductile.
(iv) Metals are good conductors of heat and electricity.
(v) Metals can form positive ions by losing electrons to non-metals.
(vi) All metals combine with oxygen to form metal oxides. Metal oxide reacts with water forms metallic hydroxide.
10. General Properties of non-metals:
i. Nonmetals are neither malleable nor ductile.
ii. They are bad conductors of heat and electricity, except for graphite, which conducts electricity.
iii. Carbon is a non-metal that can exist in different forms. Each form is called an allotrope. Diamond, an allotrope of carbon, is the hardest natural substance known and has a very high melting and boiling point. Graphite, another allotrope of carbon, is a conductor of electricity.
iv. Nonmetals can form negative ions by gaining electrons from metals.
v. Diamond, an allotrope of carbon, is the hardest natural substance known and has a very high melting and boiling point.
vi. Graphite, another allotrope of carbon is a conductor of electricity.
vii. Most non-metals produce acidic oxides when dissolving in water. On the other hand, most metals, give rise to basic oxides.
11. Alkali
metals (lithium,
sodium, potassium) are so soft that they can be cut with a knife. They have
low densities and low melting points.
12. Amphoteric oxides --
Metal oxides which react with both acids as well as bases to produce salts and
water are known as amphoteric oxides. Aluminium oxide, zinc oxide, etc., show
both acidic as well as basic behavior.
13. Alkali metals -
Most metal oxides are insoluble in water but some of these dissolve in water to
form alkalis. Sodium oxide and potassium oxide dissolve in water to produce
alkalis.
14. Highly reactive metals - Potassium
and sodium reacts so vigorously that they catch fire if kept in the open. Hence,
to protect them and to prevent accidental fires, they are kept immersed in
kerosene oil.
15. Properties of some metals-
i. At ordinary temperatures, the surfaces of metals such as magnesium, aluminium,
zinc, lead, etc., are covered with a thin layer of oxide. The protective oxide
layer prevents the metal from further oxidation.
ii. Iron
does not burn on heating but iron filings burn vigorously when sprinkled in the
flame of the burner.
iii. Copper
does not burn, but the hot metal is coated with a black coloured layer of
copper(II) oxide.
iv. Silver
and gold does not react with oxygen even at high temperatures.
16. Anodising-
Anodising is a process of forming a thick oxide layer of aluminium. Aluminium
develops a thin oxide layer when exposed to air. This aluminium oxide coat
makes it resistant to further corrosion.
17. Some Chemical reactions of metals -
i. Metals
like potassium and sodium react violently with cold water and the reaction is
so violent and exothermic that the evolved hydrogen immediately catches fire.
ii. The
reaction of calcium with water is less violent. The heat evolved is not
sufficient for the hydrogen to catch fire.
iii. Calcium
starts floating when reacting with water because of the bubbles of hydrogen gas
formed stick to the surface of the metal.
iv. Magnesium
does not react with cold water. It reacts with hot water to form magnesium
hydroxide and hydrogen. It also starts floating due to the bubbles of hydrogen
gas sticking to its surface.
v. Metals
like aluminium, iron, and zinc do not react either with cold or hot water. But
they react with steam to form the metal oxide and hydrogen.
vi. Metals
such as lead,
copper, silver, and gold do not react with
water at all. These metals are called inert metal. Copper does not react with dilute acids.
vii. Metals
react with acids to give a salt and hydrogen gas.
viii. Hydrogen gas is not
evolved when a metal reacts with nitric
acid. It is because HNO3 is a strong oxidizing agent. It
oxidizes the H2 produced to water and itself gets reduced to
any of the nitrogen oxides (N2O, NO, NO2). But magnesium
(Mg) and manganese (Mn) react with very dilute HNO3 to evolve H2 gas.
ix. Reactive metals can displace less reactive metals from their compounds in solution or molten form
18. Aqua regia, (Latin
for ‘royal water’) is a freshly prepared mixture of concentrated hydrochloric
acid and concentrated nitric acid in the ratio of 3:1. Aqua regia is a highly
corrosive, fuming liquid. It is one of the few reagents that are able to
dissolve gold and platinum..
19. General properties for ionic compounds—
i. Physical nature: Ionic compounds are solids and are somewhat hard because of the strong force of attraction between the positive and negative ions. These compounds are generally brittle and break into pieces when pressure is applied.
ii. Melting and Boiling points: Ionic compounds have high melting and boiling points. This is because a considerable amount of energy is required to break the strong inter-ionic attraction.
iii. Solubility: Electrovalent compounds are generally soluble in water and insoluble in solvents such as kerosene, petrol, etc.
iv. Conduction of Electricity: The conduction of electricity through a solution involves the movement of charged particles. A solution of an ionic compound in water contains ions, which move to the opposite electrodes when electricity is passed through the solution.
20. Reactivity Series of non metals- The reactivity series is a list of non-metals arranged in the order of their decreasing activities.
F (Fluorine) →Most reactive
Cl (Chlorine)
(Oxygen)
Br (Bromine)
I (Iodine)
S (Sulfur)
P (Red phosphorus) → Least reactive.
22. Reactivity Series of metals - The reactivity series is a list of metals arranged in the order of their decreasing activities.
K (Potassium) → Most reactive Please
Na(Sodium) stop
Ca(Calcium) calling
Mg(Magnesium) me
Al (Aluminium) a
C (Carbon) careless
Zn(Zinc) → Reactivity decreases zebra
Fe(Iron) instead
Sn(Tin) try
Pb(Lead) learning
H (Hydrogen) how
Cu(Copper) copper
Hg(Mercury) mercury
Ag(Silver) saves
Au(Gold) gold
Pt (Platinum) →platinum Least reactive
Metals above hydrogen in the Activity series can displace hydrogen from dilute acids.
23. Ionic Compound - The compounds formed by the transfer of electrons from a metal to a non-metal are known as ionic compounds or electrovalent compounds.
Ex - Mg is the cation and Cl is anion present in MgCl2.
Mg lose 2 electrons and form the cation (Mg2+)
Cl gains 2 electrons and form anion (Cl2-).
Properties of ionic compound - Ionic compounds in the solid-state do not conduct electricity because the movement of ions in the solid is not possible due to their rigid structure. But ionic compounds conduct electricity in the molten state. This is possible in the molten state since the electrostatic forces of attraction between the oppositely charged ions are overcome due to the heat. Thus, the ions move freely and conduct electricity.
24. Metallurgy- The extraction of metals from their ores and then refining them for use is known as metallurgy.
25. Gangue- Ores mined from the earth are usually contaminated with large amounts of impurities such as soil, sand, etc., called gangue.
26. Extraction of low reactive metals - The oxides of low reactive metals can be reduced to metals by heating. For example, cinnabar (HgS) is an ore of mercury. When it is heated in air, it is first converted into mercuric oxide (HgO). Mercuric oxide is then reduced to mercury on further heating. Similarly, copper which is found as Cu2S is an ore of Cu in nature that can be obtained from its ore by just heating in air.
27. Extraction of middle reactive metal – Middle reactive elements are usually present as sulfides or carbonates in nature. It is easier to obtain metal from its oxide, as compared to its sulfides and carbonates. Therefore, prior to reduction, the metal sulfides and carbonates must be converted into metal oxides.
Roasting - The sulfide ores are converted into oxides by heating strongly in the presence of excess air. This process is known as roasting.
Calcination - The carbonate ores are changed into oxides by heating strongly in limited air. This process is known as calcination.
Reduction - The metal oxides are then reduced to the corresponding metals by using suitable reducing agents such as carbon.
The highly reactive metals such as sodium, calcium, aluminium, etc., are used as reducing agents because they can displace metals of lower reactivity from their compounds.
28. Thermite reaction - The reaction of iron (III) oxide (Fe2O3) with aluminium is highly exothermic. The amount of heat evolved is so large that the Fe metals are produced in the molten state and is used to join railway tracks or cracked machine parts. This reaction is known as the thermite reaction. Fe2O3(s) + 2Al(s) → 2Fe(l) + Al2O3(s) + Heat
29. Amalgam - If one of the metals is mercury in the alloy, then the alloy is known as an amalgam.
30. Alloy - An alloy is a homogeneous mixture of two or more metals, or a metal and a nonmetal. It is prepared by first melting the primary metal, and then, dissolving the other elements in it in definite proportions. It is then cooled to room temperature.
Properties of Alloy - The electrical conductivity and melting point of an alloy is less than that of pure metals. For example, brass, an alloy of copper and zinc (Cu and Zn), and bronze, an alloy of copper and tin (Cu and Sn), is not good conductors of electricity whereas copper is used for making electrical circuits.
Solder, an alloy of lead and tin (Pb and Sn), has a low melting point and is used for welding electrical wires together.
31. Pure gold - It is known as 24-carat gold, is very soft. It is, therefore, not suitable for making jewelry. It is alloyed with either silver or copper to make it hard. Generally, in India,
22-carat gold is used for making ornaments. It means that 22 parts of pure gold are alloyed with 2 parts of either copper or silver.
32. Corrosion: The surface of some metals, such as iron, is corroded when they are exposed to moist air for a long period of time. This phenomenon is known as corrosion.
33. Prevention from Corrosion:
The rusting of iron can be prevented by painting, oiling, greasing, galvanizing, chrome plating, anodizing or making alloys.
Galvanization is a method of protecting steel and iron from rusting by coating them with a thin layer of zinc.
Alloying is a very good method of improving the properties of a metal.
When iron is mixed with nickel and chromium, we get stainless steel, which is hard and does not rust.
34. Reasons -
(i). Silver articles become black after some time when exposed to air.This is because it reacts with sulfur in the air to form a coating of silver sulfide.
(ii) Copper reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat. This green substance is copper carbonate.
(iii) Iron, when exposed to moist air for a long time, acquires a coating of a brown flaky substance called rust.
35. Electrolytic Refining: Many metals, such as copper, zinc, tin, nickel, silver, gold, etc., are refined electrolytically. In this process, the impure metal is made the anode and a thin strip of pure metal is made the cathode. A solution of the metal salt is used as an electrolyte. On passing the current through the electrolyte, the pure metal from the anode dissolves into the electrolyte. An equivalent amount of pure metal from the electrolyte is deposited on the cathode. The soluble impurities go into the solution, whereas, the insoluble impurities settle down at the bottom of the anode and are known as anode mud.
Metals above hydrogen in the Activity series can displace hydrogen from dilute acids.
23. Ionic Compound - The compounds formed by the transfer of electrons from a metal to a non-metal are known as ionic compounds or electrovalent compounds.
Ex - Mg is the cation and Cl is anion present in MgCl2.
Mg lose 2 electrons and form the cation (Mg2+)
Cl gains 2 electrons and form anion (Cl2-).
Properties of ionic compound - Ionic compounds in the solid-state do not conduct electricity because the movement of ions in the solid is not possible due to their rigid structure. But ionic compounds conduct electricity in the molten state. This is possible in the molten state since the electrostatic forces of attraction between the oppositely charged ions are overcome due to the heat. Thus, the ions move freely and conduct electricity.
24. Metallurgy- The extraction of metals from their ores and then refining them for use is known as metallurgy.
25. Gangue- Ores mined from the earth are usually contaminated with large amounts of impurities such as soil, sand, etc., called gangue.
26. Extraction of low reactive metals - The oxides of low reactive metals can be reduced to metals by heating. For example, cinnabar (HgS) is an ore of mercury. When it is heated in air, it is first converted into mercuric oxide (HgO). Mercuric oxide is then reduced to mercury on further heating. Similarly, copper which is found as Cu2S is an ore of Cu in nature that can be obtained from its ore by just heating in air.
27. Extraction of middle reactive metal – Middle reactive elements are usually present as sulfides or carbonates in nature. It is easier to obtain metal from its oxide, as compared to its sulfides and carbonates. Therefore, prior to reduction, the metal sulfides and carbonates must be converted into metal oxides.
Roasting - The sulfide ores are converted into oxides by heating strongly in the presence of excess air. This process is known as roasting.
Calcination - The carbonate ores are changed into oxides by heating strongly in limited air. This process is known as calcination.
Reduction - The metal oxides are then reduced to the corresponding metals by using suitable reducing agents such as carbon.
The highly reactive metals such as sodium, calcium, aluminium, etc., are used as reducing agents because they can displace metals of lower reactivity from their compounds.
28. Thermite reaction - The reaction of iron (III) oxide (Fe2O3) with aluminium is highly exothermic. The amount of heat evolved is so large that the Fe metals are produced in the molten state and is used to join railway tracks or cracked machine parts. This reaction is known as the thermite reaction. Fe2O3(s) + 2Al(s) → 2Fe(l) + Al2O3(s) + Heat
29. Amalgam - If one of the metals is mercury in the alloy, then the alloy is known as an amalgam.
30. Alloy - An alloy is a homogeneous mixture of two or more metals, or a metal and a nonmetal. It is prepared by first melting the primary metal, and then, dissolving the other elements in it in definite proportions. It is then cooled to room temperature.
Properties of Alloy - The electrical conductivity and melting point of an alloy is less than that of pure metals. For example, brass, an alloy of copper and zinc (Cu and Zn), and bronze, an alloy of copper and tin (Cu and Sn), is not good conductors of electricity whereas copper is used for making electrical circuits.
Solder, an alloy of lead and tin (Pb and Sn), has a low melting point and is used for welding electrical wires together.
31. Pure gold - It is known as 24-carat gold, is very soft. It is, therefore, not suitable for making jewelry. It is alloyed with either silver or copper to make it hard. Generally, in India,
22-carat gold is used for making ornaments. It means that 22 parts of pure gold are alloyed with 2 parts of either copper or silver.
32. Corrosion: The surface of some metals, such as iron, is corroded when they are exposed to moist air for a long period of time. This phenomenon is known as corrosion.
33. Prevention from Corrosion:
The rusting of iron can be prevented by painting, oiling, greasing, galvanizing, chrome plating, anodizing or making alloys.
Galvanization is a method of protecting steel and iron from rusting by coating them with a thin layer of zinc.
Alloying is a very good method of improving the properties of a metal.
When iron is mixed with nickel and chromium, we get stainless steel, which is hard and does not rust.
34. Reasons -
(i). Silver articles become black after some time when exposed to air.This is because it reacts with sulfur in the air to form a coating of silver sulfide.
(ii) Copper reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat. This green substance is copper carbonate.
(iii) Iron, when exposed to moist air for a long time, acquires a coating of a brown flaky substance called rust.
35. Electrolytic Refining: Many metals, such as copper, zinc, tin, nickel, silver, gold, etc., are refined electrolytically. In this process, the impure metal is made the anode and a thin strip of pure metal is made the cathode. A solution of the metal salt is used as an electrolyte. On passing the current through the electrolyte, the pure metal from the anode dissolves into the electrolyte. An equivalent amount of pure metal from the electrolyte is deposited on the cathode. The soluble impurities go into the solution, whereas, the insoluble impurities settle down at the bottom of the anode and are known as anode mud.
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