Why does an iron needle float on the surface of water?

An iron needle floats on the surface of water due to surface tension; option [B]. Surface tension arises from the cohesive forces between water molecules, particularly at the water-air interface. This cohesion creates a thin film on the water’s surface with higher tension than the bulk of the liquid. The surface tension acts like a “skin,” supporting lightweight objects such as the iron needle, allowing it to float. Unlike other materials, the iron needle’s density is higher than that of water, so it would typically sink. However, the strong surface tension of water counteracts the needle’s weight, effectively “holding it up” on the water’s surface. This phenomenon is observed in various contexts, from small insects walking on water to certain lightweight objects floating. Therefore, the correct option is [B] Due to surface tension, as it is the cohesive force at the water’s surface that enables the iron needle to float rather than sink.