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Which of the following statement(s) is/are correct regarding allotropes of carbon: 1. Diamond is an extremely hard, transparent crystal, with carbon atoms arranged in a tetrahedral lattice.  2. Lonsdaleite is a soft, black, flaky solid, moderate electrical conductor. 3. Graphene is the basic structural element of other allotropes, nanotubes, charcoal, and fullerenes. Select the correct code given below.

Which of the following statement(s) is/are correct regarding allotropes of carbon: 1. Diamond is an extremely hard, transparent crystal, with carbon atoms arranged in a tetrahedral lattice.  2. Lonsdaleite is a soft, black, flaky solid, moderate electrical conductor. 3. Graphene is the basic structural element of other allotropes, nanotubes, charcoal, and fullerenes. Select the correct code given below. Correct Answer 1 and 3 only

The correct answer is 1 and 3 only.

Key Points

  • Allotropes of carbon
    • The phenomenon by which an element can exist in more than one physical state is called allotropy. 
    • The allotropes of carbon can be categorized into two:
    • Amorphous Carbon Allotropes
    • Crystalline Carbon Allotropes
    • Carbon with atomic number 6 and represented by the symbol ‘C’ in the periodic table is one of the most influential elements we see around us.
    • Carbon is one of the elements which shows allotropy.
    • The allotropes of carbon can be either amorphous or crystalline (Diamond, Graphite).
    • Diamond: It is an extremely hard, transparent crystal, with carbon atoms arranged in a tetrahedral lattice. Hence, Statement 1 is correct.
    • This allotrope of carbon is a poor electrical conductor and an excellent thermal conductor.
    • Lonsdaleite: These are also called hexagonal diamonds. 
    • Graphene: It is the basic structural element of other allotropes, nanotubes, charcoal, and fullerenes. Hence, Statement 3 is correct.
    • Q-carbon: These carbon allotropes are ferromagnetic, tough, and brilliant crystal structure that is harder and brighter than diamonds.
    • Graphite: It is a soft, black, flaky solid, a moderate electrical conductor.  Hence, Statement 2 is incorrect.
    • The C atoms are bonded in flat hexagonal lattices (graphene), which are then layered in sheets.
    • Linear acetylenic carbon (Carbyne)
    • Amorphous carbon
    • Fullerenes, including Buckminsterfullerene, also known as “buckyballs”, such as C60.
    • Carbon nanotubes: Allotropes of carbon with a cylindrical nanostructure.

Related Questions

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