As which one of the following, does carbon occur in its purest form in nature ?

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Q: 91 (CDS-I/2008)
As which one of the following, does carbon occur in its purest form in nature ?

question_subject: 

Ecology

question_exam: 

CDS-I

stats: 

0,40,20,40,7,11,2

keywords: 

{'carbon': [1, 0, 4, 5], 'carbon black': [0, 0, 3, 4], 'graphite': [0, 0, 3, 9], 'coal': [0, 1, 2, 0], 'diamond': [0, 0, 3, 3], 'purest form': [0, 0, 2, 1], 'nature': [5, 1, 15, 25]}

In nature, carbon occurs as different forms such as carbon black, graphite, diamond, and coal. However, the purest form of carbon can be found as carbon black. Carbon black is produced by the incomplete combustion of hydrocarbons or the thermal decomposition of natural gas. It is a fine powder that is primarily composed of carbon particles.

Option 2, graphite, is also a form of carbon but it is not considered the purest form. Graphite is composed of layers of carbon atoms arranged in a hexagonal lattice structure. It is commonly used in pencils and as a lubricant.

Option 3, diamond, is another form of carbon but it is not the purest form. Diamond is composed of a three-dimensional structure of carbon atoms, which makes it one of the hardest known substances.

Option 4, coal, is a sedimentary rock that is primarily composed of carbon, along with other elements such as hydrogen, oxygen, and nitrogen. It is a fossil fuel that is formed from the remains of plants that lived and died millions of years ago.

Therefore, option 1, carbon black, is the correct answer as it represents the purest form of carbon in nature.