Consider the following statements Statement I: In the context of effect of water on rocks, chalk is known as a very permeable roc…

Question

Consider the following statements:

Statement I: In the context of effect of water on rocks, chalk is known as a very permeable rock whereas clay is known as quite an impermeable or least permeable rock.

Statement II: Chalk is porous and hence can absorb water.

Statement III: Clay is not at all porous.

Which one of the following is correct in respect of the above statements?

1. A. Both Statement II and Statement III are correct and both of them explain Statement I
2. B. Both Statement II and Statement III are correct but only one of them explains Statement I (Correct answer)
3. C. Only one of the Statements II and III is correct and that explains Statement I
4. D. Neither Statement II nor Statement III is correct

Correct Answer

Option B — Both Statement II and Statement III are correct but only one of them explains Statement I

Detailed Solution & Explanation

The correct answer is Both Statement II and Statement III are correct but only one of them explains Statement I.

Key Points

• Chalk is both porous and permeable — water can pass through it (Statement II correctly explains Statement I for chalk).
• Clay is porous (has many tiny pores between its fine particles) but its pores are so small and poorly connected that water cannot pass through — making it impermeable despite having porosity.
• Statement III claiming clay has "no porosity at all" is technically incorrect since clay does have porosity; its impermeability comes from small, poorly connected pores.
• Both II and III are correct but only Statement II fully explains Statement I.