Question

Chemically, diamond is:
(A) A mixture of metal carbonates
(B) Pure carbon
(C) A pure form of sand
(D) A mixture of calcium and magnesium phosphates

Answer 1

Hint :Diamond is a crystal structure, which at room temperature and pressure is a solid form of an element. It is a very stable structure and is the hardest naturally-occurring mineral. To achieve such stability, certain structural properties are essential and this makes diamonds distinct from other substances.

Complete Step By Step Answer:
Diamond is a solid crystalline mineral.
It is one of the hardest naturally-occurring minerals.
Chemically, it is highly stable and hardly reacts with any substance and does not change its own composition either.
Due to this high stability, options (A) and (D) are not possible as metal carbonates are highly reactive. Therefore, option (A) and (D) can be ruled out.
As diamond is the hardest mineral, it implies that it is structurally very stable as well. Option (C) saying diamond is a pure form of sand is not possible as such high stability is not possible in sand. Therefore, option (C) can be ruled out.
Carbon is a tetravalent element which can form strong bonds and can form highly stable compounds.
Diamond is an allotrope of carbon and it is present in its pure form.
Therefore the answer to this question is option (B) chemically, diamonds are made of pure carbon.
Covalent bonds are formed with carbon atoms, which then form an octahedral crystal habitat and that’s how diamond gets its stability.
Diamonds also have a high tolerance of temperature and pressure.

Additional Information:
Although carbon also forms another chemically stable structure called graphite, diamond almost never converts to it – owing to its chemical stability.

Note :
You need to learn the chemical and structural properties of carbon compounds as these questions are very common. The bonding of carbon is also a very important concept to keep in mind. Not all carbon compounds are structured in the same way, these distinctions are important to know.