Metals

Iron (Fe)

Physical properties

1. It is shiny grayish white metal.
2. It is malleable and ductile.
3. It is a magnetic substance but turns non magnetic above 770°C.

Uses of iron

1. It is used to make pipes, rods, iron sheet which are used in construction.
2. It is used to make various weapons, machinery, tools etc.
3. It is used to manufacture steel.

Aluminium (Al)

Physical properties

1. It is a shiny, silvery white colored metal.
2. It is highly malleable and ductile.
3. It is very good conductor of heat and electricity.
4. It is very light and strong metal.

Uses of aluminum

1. It is used to make body parts of vehicle aeroplane as it is light metal.
2. It is used to make electric wires.
3. It is used in packaging of food as cans, foils etc.
4. It is used to make silver paint.

Copper (Cu)

Physical properties

1. It is a shiny reddish brown metal.
2. It is very good conductor of heat and electricity.
3. It is highly malleable and ductile.

Uses of copper

1. It is used to make various utensils.
2. It is used to make electric wires.
3. It is also used to make coins, statues, medals, ornaments etc

Silver (Ag)

Physical properties

1. It is shiny white metal.
2. It is highly malleable and ductile.
3. It is good conductor of heat and electricity.

Use of silver

1. It is used to make jewellery, coins and decorative articles.
2. It is used in photographic film and x-ray.
3. It is used in making medicine, filling cavity of teeth.

Gold (Au)

Physical properties

1. It is shiny yellowish metal.
2. It is highly malleable and ductile.
3. It is good conductor of heat and electricity.

Uses of gold

1. It is used to make various ornaments.
2. It is used to make Various metals and coins.
3. It is used to make various medicines.

Important alloys made of copper

Electronic configuration

Iron (Fe)

Atomic number = 26

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d⁶

Aluminum (Al)

Atomic number = 13

1s², 2s², 2p⁶, 3s², 3p¹

Copper (Cu)

Atomic number = 29

1s², 2s², 2p⁶, 3s², 3p⁶, 4s¹, 3d¹⁰

Silver (Ag)

Atomic number = 47

1s², 2s², 2p⁶, 3s², 3p⁶, 3d¹⁰, 4s²,  4p⁶, 4d¹⁰, 5s¹

Gold (Au)

Atomic number = 79

1s², 2s², 2p⁶, 3s², 3p⁶, 3d¹⁰, 4s², 4p⁶, 4d¹⁰, 4f¹⁴, 5s², 5p⁶, 5d¹⁰, 6s¹

Answer the questions

a. Write two reasons why metals like copper and aluminum are used to make cooking vessels.

It is due to following reasons

1. They are good conductor of heat.
2. They have high melting point.
3. They are malleable.

b. Which the properties of metals enable us to use them as electric wire?

1. They are good conductor of electricity.
2. They are ductile in nature.

c. Gold is found in native form in pure state but iron is not found freely in nature. why?

This is because gold is least reactive metal and doesn’t react with other elements in ordinary condition but iron is reactive metal so reacts with other elements and hence, it is not found freely in nature.

d. Why can we not put pickles in metallic vessels?

Acids are present in pickles which react with metal so if we put pickle in metallic container, the chemical reaction between acid and metal can damage the quality of pickle.

e. Aluminum or its alloy but not an iron is used to make body of aeroplane although iron is much harder than aluminum. Why?

This is because of following reasons

1. Iron is heavier than aluminum so use of aluminum decreases its weight.
2. Iron gets rusted but aluminum not, as it is durable.

f. The surface of gold remains shiny for ever but the surface of metal like iron and copper tarnish in long run. why?

This is because gold is least reactive metal so it doesn’t react with other elements and remains shiny forever but metals like iron and copper are reactive to some extent due to which they react with other elements such as oxygen and their surface tarnish.

g. Write two differences between properties of aluminum and iron.