What are brittle bodies?

Hint: body is said to be brittle if on applying stress (that means force per unit area) breaks up into pieces. Mirror, graphite, crystals all are brittle materials.

Complete step by step answer:
When used in material science, it is generally applied to materials that fail when there is little or no plastic deformation before failure.
One of the proofs of this may be the breaking of the wooden stick because when a wooden stick breaks it just gets broken without any plastic deformation, however by applying different chemicals or procedures woods are transformed into some carvings, curves, etc.
A material is said to be brittle material if, when subjected to the stress, it breaks with little elastic deformation and without any significant plastic deformation.
Elastic deformation – The property of certain materials that enables them to return to their original dimensions after applied stress has been removed.
Elastic deformation is seen within the elastic limit of the material.
This is in accordance with Hooke's law.
Plastic deformation- The property of certain materials that enables them to keep the shape deformed dimensions after applied stress has been removed.
The point after which this phenomenon is observed is called the plastic limit of that material.
Brittle materials absorb relatively little / less energy prior to their fracture.
Elastic modulus (\[\gamma \]) – it is the ratio of the stress applied to the body to the strain produced.

Note:
Many steel materials or types of steel become brittle at low temperatures.
In brittle materials, breaking is often accomplished with a cracking sound or snapping sound.
In brittle materials, we can put ceramics (china-clay pots), glasses (which don’t deform plastically), and some polymers (polystyrene) many alloys become brittle at a low temperature depending upon their composition and processing.