Two identical wires of rubber and iron are stretched by the same weight, then the number of atoms in the iron wire will be

Explanation

When identical wires of rubber and iron are stretched by the same weight, the number of atoms in the iron wire will be more than that in the rubber wire. This is due to the higher atomic density of iron compared to rubber. Iron is a metal with closely packed atoms, while rubber is a polymer with more space between its molecules. Hence, even when both wires are of the same dimensions, the iron wire contains more atoms. Option A is incorrect because it assumes the atomic density of rubber and iron to be the same, which is not true. Option B is incorrect as it wrongly assumes iron to be less dense than rubber. Option D is incorrect because it dismisses the correct option, which addresses the material properties accurately.