Allotropes of carbon: Identify the hardest and the softest allotrope among the given pairs. Use known mechanical properties of carbon forms (sp³ vs sp²/amorphous). Choose the correct pair.
General Knowledge
General Science
Difficulty: Easy
Choose an option
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ACoke is the hardest; graphite is the softest
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BDiamond is the hardest; coke is the softest
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CDiamond is the hardest; graphite is the softest
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DDiamond is the hardest; lamp black is the softest
Answer
Correct Answer: Diamond is the hardest; graphite is the softest
Explanation
Given data
- Compare carbon allotropes for hardness.
Concept/Approach Diamond (3D sp³ network) has extremely strong covalent bonds → highest hardness. Graphite has layered sp² sheets with weak interlayer forces → very soft and lubricating.
Final Answer Diamond is the hardest; graphite is the softest