Metals
They are elements which lose electrons to form cations and are electropositive, e.g Iron,Zinc,Calcium etc.
Physical Properties of Metals
1.Ductile:They can be drawn into wires.Gold is the most ductile metal 1 gram of gold can be drawn into wire of 2km of length.Silver, Aluminium and copper are also very ductile.
2.Malleable:They can be beaten into thin sheets
3.Conductivity:As they are electropositive they have free electrons so they are good conductor of heat and electricity.Silver is best conductor of electricity.
4.Nature:They are generally found in solid form, mercury is the only metal which is liquid at room temeprature
5.Sonorous:They produce ringing sound
6.Desnsity:They have very high density
7.Melting and Boiling point:They have very high melting and boiling point
8.Lustre:They are shiny and lustrous in nature
9.Colour:Most metals are of Silvery grayish colour except gold and copper.Gold is yellow in colour whereas copper is brown in colour.
Some Exceptions to the rule
1.Sodium,Lithium and Potassium are soft metals and can be cut with knife.These metals are also called alkali metals
2.Lead is poor conductor of electricity
3.Zinc is neither malleable nor ductile
4.Mercury is liquid at Room Temperature
5.Gallium and Cesium have low melting points. They melt in the palm of the hand
6.Gold,Platinum and silver are noble metals as they are non reactive
7.Aluminium is the most abundant metal in Earth's crust
8.Sodium potassium are kept in keroscene.If they are kept in open or in water they tend to catch fire as they react violently with oxygen.
Chemical Properties of Metals
1.Metals react with oxygen to form Metal Oxides
2.Metal oxides are basic in nature
3.Metals displace hydrogen from dilute acids
4.A more reactive metal displaces less reactive metal from its salt solution
Reactivity Series : The series of metals in which they are arranged in order of their decreasing reactivity is called reactivity of activity series.
Here is a Mnemonic device to learn the reactivity series and chemical symbols of all the metals
Kedar Nath Ca Mali Aaloo Zara Feeke Pakata Hai
K Potassium
Na Sodium
Ca Calcium
Mg Magnesium
Al Aluminium
Zn Zinc
Fe Iron
H Hydrogen
Cu Copper
Hg Mercury
Ag Silver
Au Gold
Above, the metals have been arrange in decreasing order of their reactivity potassium is most reactive where as Gold is the least reactive metal.A more reactive metal will displace less reactive metal from its salt solution.This kind of reactiion is called Displacement reaction.
Suppose if we put Iron nail into copper sulphate solution.Iron nail will displace copper from its salt solution because iron is more reactive than copper.But if we were to put copper pieces into iron sulphate solution nothing will happen as copper is below iron in reactivity series.
Different Types of Iron
Pig Iron:Pig iron is composed of about 93%
Wrought Iron:
Uses of Metals
The elements and compounds which are found naturally in the earth crust are called minerals.
Ores The minerals from which metals can be extracted easily and profitably are called ores. An ore contains good percentage of metals and less impurities.
Aluminium's ore is bauxite
Copper's ore is cuprite
Iron's ore is haematite
lead's ore is galena
Magnesium's ore is epsom salt
b) Nonmetals are solid, liquid and gas at room temperature.
c) Nonmetals are not good conductors of heat and electricity.
d) Nonmetals have low melting and boiling points.
e) Nonmetals are soft.
f) Nonmetals form acidic or neutral oxides when react with air
g) Nonmetals do not react with water and steam.
h) Nonmetals do not displace hydrogen with dilute acids.
i) Nonmetals form covalent chlorides with chlorine.
j) Nonmetals react with hydrogen to form stable hydrides.
Followings are exceptional Nonmetals which
a) Is liquid at room temperature – bromine
b) Are lustrous – iodine and graphite
c) Is hardest – diamond
d) Are good conductors of electricity – carbon and gas carbon
e) Is most abundant in earth crust – oxygen
f) Show allotropy – carbon, sulphur and phosphorus
g) They do not conduct electricity because they do not contain ions in molten state
h).Sulphur is highly reactive non metal and is kept in water, if kept in open it reacts vigoursly and catches fire
USES of Non Metals
Difference Between Metals and Non Metals
They are elements which lose electrons to form cations and are electropositive, e.g Iron,Zinc,Calcium etc.
Physical Properties of Metals
1.Ductile:They can be drawn into wires.Gold is the most ductile metal 1 gram of gold can be drawn into wire of 2km of length.Silver, Aluminium and copper are also very ductile.
2.Malleable:They can be beaten into thin sheets
3.Conductivity:As they are electropositive they have free electrons so they are good conductor of heat and electricity.Silver is best conductor of electricity.
4.Nature:They are generally found in solid form, mercury is the only metal which is liquid at room temeprature
5.Sonorous:They produce ringing sound
6.Desnsity:They have very high density
7.Melting and Boiling point:They have very high melting and boiling point
8.Lustre:They are shiny and lustrous in nature
9.Colour:Most metals are of Silvery grayish colour except gold and copper.Gold is yellow in colour whereas copper is brown in colour.
Some Exceptions to the rule
1.Sodium,Lithium and Potassium are soft metals and can be cut with knife.These metals are also called alkali metals
2.Lead is poor conductor of electricity
3.Zinc is neither malleable nor ductile
4.Mercury is liquid at Room Temperature
5.Gallium and Cesium have low melting points. They melt in the palm of the hand
6.Gold,Platinum and silver are noble metals as they are non reactive
7.Aluminium is the most abundant metal in Earth's crust
8.Sodium potassium are kept in keroscene.If they are kept in open or in water they tend to catch fire as they react violently with oxygen.
Chemical Properties of Metals
1.Metals react with oxygen to form Metal Oxides
2.Metal oxides are basic in nature
3.Metals displace hydrogen from dilute acids
4.A more reactive metal displaces less reactive metal from its salt solution
Reactivity Series : The series of metals in which they are arranged in order of their decreasing reactivity is called reactivity of activity series.
Here is a Mnemonic device to learn the reactivity series and chemical symbols of all the metals
Kedar Nath Ca Mali Aaloo Zara Feeke Pakata Hai
K Potassium
Na Sodium
Ca Calcium
Mg Magnesium
Al Aluminium
Zn Zinc
Fe Iron
H Hydrogen
Cu Copper
Hg Mercury
Ag Silver
Au Gold
Above, the metals have been arrange in decreasing order of their reactivity potassium is most reactive where as Gold is the least reactive metal.A more reactive metal will displace less reactive metal from its salt solution.This kind of reactiion is called Displacement reaction.
Suppose if we put Iron nail into copper sulphate solution.Iron nail will displace copper from its salt solution because iron is more reactive than copper.But if we were to put copper pieces into iron sulphate solution nothing will happen as copper is below iron in reactivity series.
Different Types of Iron
Pig Iron:Pig iron is composed of about 93%
iron, from 3% to 5% carbon, and various amounts of
other elements. Pig iron is comparatively weak and
brittle; therefore, it has a limited use and approximately
ninety percent produced is refined to produce steel.
Wrought Iron:
Wrought iron is made from
pig iron with some slag mixed in during manufacture.
Almost pure iron, the presence of slag enables wrought
iron to resist corrosion and oxidation. The chemical
analyses of wrought iron and mild steel are just about
the same. The difference comes from the properties
controlled during the manufacturing process. Wrought
iron can be gas and arc welded, machined, plated, and
easily formed; however, it has a low hardness and a
low-fatigue strengthUses of Metals
- Copper and aluminium wire are used to carry electric current.
- Copper, aluminium and iron are used to make domestic utensils and factory equipment.
- Thin foils of aluminium are used for wrapping cigarettes, medicines, confectionery, etc.
- Aluminium is used for making angles, doors, pipes, etc. which are used in the construction of houses.
- Metals such as sodium, titanium, zirconium, etc. are used in generation of nuclear energy and in space science projects.
- Mercury is used in thermometers.
- Magnesium metal is used as a strong reducing agent to prepare other metals.
- Gold and silver metals are used to make jewellery.
- Thin foils of silver and gold are used to decorate sweets.
- Uranium metal is used to generate nuclear energy.
- Titanium metal is very hard, resistant to corrosion, light, has high melting point and is good conductor of heat and electricity. Because of its unique and useful properties titanium is sometimes called ‘the wonder metal’.
- Titanium and its alloys are extensively used in:
- Jet and gas turbine engines.
- Aircrafts frames.
- Marine equipment.
- Chemical plants, and
- Military hardware.
- Titanium due to its special application is sometimes referred as a strategic element.
The elements and compounds which are found naturally in the earth crust are called minerals.
Ores The minerals from which metals can be extracted easily and profitably are called ores. An ore contains good percentage of metals and less impurities.
Aluminium's ore is bauxite
Copper's ore is cuprite
Iron's ore is haematite
lead's ore is galena
Magnesium's ore is epsom salt
Nonmetals : The elements that gain electrons and form negative ions are called nonmetals. They are also called electronegative elements. E.g. chlorine, sulphur, oxygen, bromine, phosphorus, nitrogen, etc.
Physical and Chemical Properties a) Nonmetals are not malleable and ductile but they are brittle.b) Nonmetals are solid, liquid and gas at room temperature.
c) Nonmetals are not good conductors of heat and electricity.
d) Nonmetals have low melting and boiling points.
e) Nonmetals are soft.
f) Nonmetals form acidic or neutral oxides when react with air
g) Nonmetals do not react with water and steam.
h) Nonmetals do not displace hydrogen with dilute acids.
i) Nonmetals form covalent chlorides with chlorine.
j) Nonmetals react with hydrogen to form stable hydrides.
Followings are exceptional Nonmetals which
a) Is liquid at room temperature – bromine
b) Are lustrous – iodine and graphite
c) Is hardest – diamond
d) Are good conductors of electricity – carbon and gas carbon
e) Is most abundant in earth crust – oxygen
f) Show allotropy – carbon, sulphur and phosphorus
g) They do not conduct electricity because they do not contain ions in molten state
h).Sulphur is highly reactive non metal and is kept in water, if kept in open it reacts vigoursly and catches fire
USES of Non Metals
Difference Between Metals and Non Metals
Corrosion. :
The process of slowly eating away of metals due to their conversion
into oxides, carbonates, sulphides, sulphates, etc by the action of
moisture and gases is called corrosion
Conditions for rusting are – presence of moisture and presence of air.
Prevention of rusting : Rusting of iron can be prevented
Prevention of rusting : Rusting of iron can be prevented
a) by painting, applying grease or oil,
b) galvanization,
c) chrome plating,
d) anodizing,
e) making alloys.
Galvanization:The process of forming a thick layer of zin over other metal is called Galvanization .
Galvanization:The process of forming a thick layer of zin over other metal is called Galvanization .
Self protecting metals : The
metals that react with air to form a thin layer of their oxide over
them to protect from further corrosion of oxidation are called self
protecting metals. E.g. aluminium, zinc, magnesium, lead, etc.
Anodizing : The process of forming a thick layer of aluminium oxide over aluminium metal is called anodizing.
During anodizing process : A clean aluminum article is made anode and is electrolyzed with dil H2 SO4 . The oxygen gas produced at anode reacts with aluminium to make a thicker protective layer of its oxide.
Anodizing : The process of forming a thick layer of aluminium oxide over aluminium metal is called anodizing.
During anodizing process : A clean aluminum article is made anode and is electrolyzed with dil H2 SO4 . The oxygen gas produced at anode reacts with aluminium to make a thicker protective layer of its oxide.
4) Chemical properties of metals and non metals:-
a) Reaction with oxygen:-
Metals react with oxygen to form metallic oxides. These oxides are basic oxides because they react with water to form bases. Eg. Magnesium burns in air to form magnesium oxide. Magnesium reacts with water to form magnesium hydroxide.
2 Mg + O2--à2 MgO
MgO+ H2O-à Mg(OH)2
Non metals react with oxygen to form non metallic oxides. These oxides are acidic oxides because they react with water to form acids.
Eg. Sulphurburns in air to form sulphurdioxide. Sulphurdioxide reacts with water to form sulphurousacid.
S + O2-àSO2
SO2+ H2O---à H2SO3
b) Reaction with water:-
Metals react with water to form metal hydroxides and hydrogen.
Eg. Sodium reacts with water to form sodium hydroxide and hydrogen.
2 Na + 2 H2O 2 Na OH + H2
Magnesium reacts with water to form magnesium hydroxide and hydrogen.
Mg + H2O Mg(OH)2+ H2
Non metals do not react with water.
c) REACTION WITH ACIDS:-
Metals react with acids to form metallic salts and hydrogen.
Eg. Zinc reacts with dilute hydrochloric acid to form zinc chloride and hydrogen.
Zn + 2 HCl ---------------àZnCl2+ H2
Most non metals do not react with acids.
Some non metals like sulphur reacts with concentrated nitric acid to forn sulphur dioxide, nitrogen dioxide and water.
S + 4 HNO3 -----------à SO2+ 4 NO2+2 H2O
d) Metals replace metals:-
A more reactive metal replaces a less reactive metal from its salt solution.
Eg. Magnesium replaces copper from copper sulphate solution to form magnesium sulphate and copper.
Mg + CuSO4----------------à MgSO4+ Cu
Zinc replaces copper from copper sulphate solution to for zinc sulphate and copper.
Zn + CuSO4------------------à ZnSO4 + Cu
Iron replaces copper from copper sulphate solution to form iron sulphate and copper
Fe + CuSO4----------à FeSO4+ Cu
Based on the reactivity of metals, they can be arranged in the decreasing order of their activity.
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ReplyDeleteGood and simple to understand.
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