Which statement best describes physical weathering?

• A. Rocks melt into liquid due to heat.
• B. Rocks disintegrate without chemical changes.
• C. Rocks dissolve in water through chemical reactions.
• D. Rocks change mineral composition during weathering.

Answer: (B)

Physical weathering is the breaking of rocks into smaller pieces without altering the minerals’ chemical makeup. That means the rock fragments stay the same substance, just in smaller sizes. This is exactly what disintegration without chemical changes describes. Processes like frost wedging, freeze–thaw, abrasion, and root growth physically fracture rock, increasing surface area and making it more vulnerable to chemical weathering later.

The other statements point to chemical weathering or phase changes: melting describes a change of state (solid to liquid) rather than breaking into pieces, chemical dissolution involves minerals reacting with water and forming new substances, and changing mineral composition means new minerals form. Those are chemical weathering processes, not physical weathering.