Directions: Read the Assertion (A) and Reason (R) carefully and choose the correct alternative. Assertion (A): Graphite is slippery in touch and is used as a solid lubricant in many applications. Reason (R): In graphite, each carbon atom has free electrons that are delocalised and can move within layers of atoms.

Introduction / Context:
This Assertion and Reason question tests understanding of the structure and properties of graphite, an allotrope of carbon. Graphite is widely used as a dry lubricant and is known for both its slippery feel and its ability to conduct electricity. The question asks whether the presence of free electrons in graphite is the correct explanation for its slippery nature. This links concepts from chemistry and physics, especially bonding and material properties.

Given Data / Assumptions:

• Graphite is an allotrope of carbon with a layered structure.
• Assertion (A) states that graphite is slippery and used as a lubricant.
• Reason (R) states that graphite has free electrons.
• We assume standard textbook information about graphite bonding and properties.

Concept / Approach:
To answer correctly, we must treat the truth of the Assertion and the truth of the Reason separately. After that, we must check whether the Reason actually explains the stated property. Graphite consists of carbon atoms arranged in hexagonal sheets. Each carbon is bonded to three others, leaving one electron delocalised in a pi system over the sheet. These delocalised electrons give graphite electrical conductivity along the layers. The slippery nature, however, arises mainly from weak forces between layers, not directly from free electrons.

Step-by-Step Solution:
Step 1: Graphite is indeed used as a lubricant, for example in locks or machinery, especially where wet oil or grease is not suitable. It feels soft and slippery to touch. So Assertion (A) is true. Step 2: In the graphite structure, each carbon atom uses three electrons to form sigma bonds with three neighbouring atoms, creating flat hexagonal layers. The fourth valence electron becomes delocalised over the sheet. Step 3: These delocalised or free electrons are responsible for electrical conductivity of graphite along the layers. Therefore, Reason (R) stating that graphite has free electrons is also true. Step 4: The slippery property is mainly due to the weak van der Waals like forces between the parallel layers of carbon atoms. Because interlayer forces are weak, layers can slide over each other easily under small shear force, giving graphite a lubricating character. Step 5: Thus, while Reason (R) is factually correct, it does not describe the real cause for slipperiness. It explains another property, namely electrical conductivity, rather than lubrication.

Verification / Alternative check:
Chemistry textbooks usually list graphite properties such as softness, lubricating nature, electrical conductivity, and high melting point, and then relate each property to specific structural features. They clearly connect delocalised electrons to conductivity, and interlayer forces to slipperiness. Revisiting such diagrams of hexagonal layers and reading the explanations confirms that the given Reason is not the direct explanation for the behaviour mentioned in the Assertion.

Why Other Options Are Wrong:
The option claiming that both Assertion and Reason are true and Reason correctly explains the Assertion is incorrect because the explanation is linked to a different property. Options that call either Assertion or Reason false contradict well established facts about graphite. The option that claims both are false is clearly wrong as well, because graphite is a well known solid lubricant and has delocalised electrons.

Common Pitfalls:
Students often assume that any true scientific sounding statement automatically explains another statement about the same material. This question reminds you to separate the role of structure in different properties. Always check whether the stated Reason matches the specific property mentioned in the Assertion, instead of just checking overall truth.

Final Answer:
Both Assertion (A) and Reason (R) are true, but Reason (R) does not correctly explain Assertion (A), so the correct option is Both Assertion (A) and Reason (R) are true, but Reason (R) does not correctly explain Assertion (A).