Physical Properties of Metals
We use materials for various purposes everyday.
Iron, copper, silver are some of the common materials used in making coins, utensils, jewellery, car parts and a host of other things.
These materials can be divided into different categories on the basis of their physical properties
One such classification is into metals, non metals and metalloids.
In this story, we will look at a few properties which help us define metals.
1. Metals are generally found in the Solid State
Copper, silver, iron and gold are all solids under normal conditions.
But metals like gallium and caesium are special. These solids melt easily by taking up the heat from the surroundings.
The metal, mercury is an exceptional case.
It is found in the liquid state at room temperature.
2. Almost all metals are shiny.
That is metals posses a property called lustre.
An exception to this is lead, which appears dull.
3. Metals are hard and have high density.
So, metals such as aluminium, iron are used in heavy industries and in making utensils.
But sodium and potassium are exceptions. They are so soft that they can be cut with a knife.
4. Metals produce a ringing sound when hit.
This property of metals to produce a ringing sound is called sonority.
Beautiful music can be created based on the sonority of different metals.
Being soft sodium and potassium do not show this property.
5. Metals are malleable and ductile
Malleability is the property of a metal where it can be hammered into sheets like aluminium foils.
Ductility, on the other hand, is the property of a metal where it can be drawn into wires. Such as copper wires used in electric wiring.
Metals like gold are so ductile that just from 1 gm gold, we can draw wires over the length of 3 km
However metals like mercury and sodium are neither malleable nor ductile.
6. Metals are good conductors of electricity and heat.
In fact, silver is the best conductor of electricity.
Silver being more expensive, is replaced by other conductive metals like copper for most electrical purposes.
Further, metals such as iron and aluminium being a good conductor heat are used for cooking purposes.
Metals are found in solid state and are very hard.
Metals are malleable, ductile, sonorous and lustrous
Metals are good conductors of heat and electricity.