Why can a needle float on water,and small insects walk on water?
Water is composed of hydrogen and oxygen. The hydrogen is positive and the oxygen is negative, and they are like the different poles of a magnet. When water molecules are floating around in a liquid, they will arrange themselves so that the positive bits of one molecule are up against the negative bits of another molecule – almost like throwing a hundred magnets into a bag. They will arrange themselves positive to negative, and form a big clump of magnets that are stuck together. Pulling apart the water molecules is like trying to pull apart the magnets. It requires some force. In order to penetrate the surface of the water you have to shove the water molecules apart. This is what surface tension is – the force of attraction between the water molecules at the surface of the water. When a very light object rests on the water (one with a lot of surface area in comparison to its weight) the force of gravity is just not enough to push the water molecules apart, so the object on the surface
