Question

Are‌ ‌diamonds‌ ‌brittle?‌

Answer 1

Hint:The diamond is an allotrope of carbon and the answer for the question is easily understandable if we know the applications of diamonds and the nature of bonding present between the atoms in the diamond structure.

Complete step-by-step answer:Before going into the answer of the question, let us discuss a few facts about diamonds which will be helpful for concluding into the solution.
Diamonds are the allotropes of pure carbon. The pure form of carbon has mainly two common allotropes, graphite and diamond. Diamond exists in solid form.
In diamond the carbon atoms are $s{{p}^{3}}$hybridized. The structure of the diamond is the reason for the hardness. The carbon atoms are arranged in tetrahedral fashion and the tetrahedral is attached to four other neighbors and this extended bonding results in a three dimensional framework. The bonds formed are strong and rigid. So now we know the reason for the hardness of the diamond. It is one of the hardest materials known and because of its hardness it is also used for cutting material and for polishing them.
Now we have to check whether it is brittle. Diamond is hard enough but it is brittle also. The real meaning of hardness is the property of the materials which cannot undergo the plastic deformation. To undergo the plastic deformation the materials should have to break the chemical bonds present in them and this physical property completely depends on the type of bonding and the arrangement of the atoms of the material concern. Another way of defining hardness is that the amount of energy a material can absorb energy before it gets fracture by the energy applied. And in the metals if we apply the energy, then the energy is made available for plastic deformation and it does not get cracked instead it will only result in denting of the material.
But in the case of diamond it is held by the strong covalent bonds and it won't absorb the energy by the plastic deformation mechanism, instead the energy made available is used for cracking and the diamond will break into pieces like other materials which have brittle character.
So finally we could conclude that the diamond is hard but still it is brittle in nature.

Note:Because of the brittle nature of the diamond it is used in jewelry making with various designs. The diamond does not show malleable character, i.e. it is the ability of the material to deform into thin sheets under given pressure. And diamond is also a non-ductile material, i.e. it cannot be drawn into thin wires. The structure is also a bad conductor of electricity.