Question 1 Define the term malleability?
Question 2 Define the term ductility?
Question 3 Why cooking utensils are made up of metals?
Question 4 Name 2 metals which are malleable?
Question 5 Why metals are used in making jewellery?
Question 6 Why metals are used for making bells?
Question 7 Why iron is used in construction of bridges,machines,railway lines ?
Question 8 Name 2 metals which are soft and can be easily cut with a knife?
Question 9 If a metal coin is dropped on floor,it produces a ringing sound.What is this property of metals known as?
Question 10 Why copper metal is used for making electric wires?
Question 11 What is meant by saying that metals are lustrous?
Question 12 We can not hold the metallic pan directly.why?
Properties of metals
1)Metals are malleable:This means that metals can be beaten into thin sheets with hammer.
If we take a piece of aluminium metal and beat it with a hammer,we will find that the piece of aluminium metal turns into a thin aluminium sheet,without breaking.Thus we can say that aluminium metal is malleable.
The property which allow the metals to be hammered into thin sheets is called malleability.
Gold and silver are the best malleable metals.
Aluminium and copper are also highly malleable.
It is due to the property of malleability that metals can be bent to form objects of different shapes by beating with a hammer.
2)Metals are Ductile:The metals can be drawn into thin wires.
Gold and silver are the best ductile metals.Copper and aluminium are also very ductile and can be drawn into thin copper wires and aluminium wires.
Iron,magnesium and tungsten metals are quite ductile and can be drawn into wires.Iron wires are used for making wire gauzes.Magnesium wires are used in science experiments.
Thin wires of tungsten metals are used for making the filaments of electric bulb.
The property which allow the metals to be drawn into wires is called ductility.
3)Conductivity:Metals allow heat and electricity to pass through them easily.
Copper,silver,gold,aluminium,iron metals are good conductors of heat.
Silver metal is the best conductor of heat.Cooking utensils are made up of metals because metals are good conductor of heat.Being a good conductor,metallic bottom of cooking utensils transfers the heat of gas stove quickly to food kept inside it.
We cannot hold the metal pan directly because it will conduct the heat quickly to our hand causing burns.
4)Lustre:Metals have a shiny appearance.
The shiny appearance of metals makes them useful in making jewellery and decorative pieces.
For Ex:Gold and silver are used for making jewellery because they are bright and shiny.
5)Strength:They have high tensile strength and can hold large weights without breaking.
For Ex:Iron metal is very strong having a high tensile strength.Due to this iron metal is used in the construction of bridges,railway lines,machines,vehicles and chains etc.
Sodium and potassium metals are not strong.
6)Sonorousness:Metals make a ringing sound when we strike them.
If we drop a metal coin or a metal utensil on the floor of our house,we hear a ringing sound.
When the hammer of an electric bell strikes the metal gong,even then a ringing sound is produced.
Metal sheets are used for making bells.
7)Hardness:Most of the metals cannot be cut easily.
If we try to cut a thin sheets of iron metal with a pair of scissors,we will find that it is very very difficult to cut the sheet of iron.This is because iron metal is very hard.
A thin sheet of aluminium metal can be cut easily by using scissors.This means that aluminium is less hard.
Sodium and potassium metals are soft and can be easily cut with a knife.