Question

Why does a grease needle float over the surface of water?

Answer 1

the grease lowers the surface tension of the needle enough that water can't wet it, and the mass of the needle is insufficient to break the surface film.

Answer 2

Answer:

A needle floats on water due to surface tension. Water has its own surface tension, that is, the molecules of the water inside exert a tension force on the surface molecules. When a needle is placed on the surface, the surface tension is broken and the needle sinks