Chemistry
Answer
In the free state —
carbon occurs free in nature in the crystalline form [i.e. crystal] as diamond & graphite & in the
amorphous form [impure] as coal formed below the earth's surface.
In the combined state —
- Carbon occurs as carbon dioxide in the atmosphere [about 0.03% by vol.]
- It also occurs as hydrocarbons in natural gas & petroleum.
- In the solid state in wood [cellulose].
- In plants & animals as carbohydrates & in minerals as limestone - CaCO3
Related Questions
Differentiate between the two branches of chemistry - organic and inorganic chemistry with suitable examples.
Define the term 'allotropy'. Give a reason why carbon exhibits allotropy.
Name two crystalline and four amorphous allotropes of carbon.
Compare the structure of the crystal of diamond & graphite with special reference to the reason for diamond being the hardest natural substance while graphite one of the softest. Compare the electrical & thermal conductivity of the two crystalline allotropes of carbon.