Identify an allotrope of carbon that is smooth and slippery.

The correct answer is Graphite.

Key Points

• Graphite is an allotrope of carbon that is known for its smooth and slippery texture.
• This characteristic makes graphite useful as a lubricant and as the "lead" in pencils.
• It is composed of stacked layers of carbon atoms arranged in a hexagonal lattice.
• This structure leads to the characteristic slipperiness, as the layers can slide over each other easily.

Additional Information

• Lead is a chemical element but not an allotrope of carbon.
• Fullerene is also an allotrope of carbon but is not typically described as smooth and slippery.
• Instead, fullerenes have a unique structure resembling balls or cylinders.
• Similarly, diamond, while an allotrope of carbon, is known for its hardness and brilliance.