Question

When we think of rust, the first image is that of a metallic object covered with the reddish-brown colour. However, rust is also possible on rocks. How can we explain this phenomenon?

• A. The water is absorbed by minerals present in rocks that leads to expansion and contraction.
• B. The carbonation leads to carbonic acid slowly disintegrating rocks.
• C. Rusting is caused due to oxidation of iron present within rocks.
• D. The rusting of rocks compromises its internal structure.

Answer 1

Answer: (C), (D)

The correct options are
C Rusting is caused due to oxidation of iron present within rocks.
D The rusting of rocks compromises its internal structure.

Oxidation occurs on some types of rocks because of the presence of iron in them. The rust that develops on the rock gets removed easily, which loosens the original structure of the rock. It makes it weak and over time breaks it down.