In an oil molecule, however, positive and negative charges are spread out pretty evenly. Molecules like this are called nonpolar molecules. The polar molecules stick together so well that the nonpolar molecules get left out. This means that one cannot be dissolved in the other. Liquids that will mix completely are soluble , or miscible .
Oil is less dense than water.
A drop of water actually weighs more than a drop of oil that is exactly the same size. As a result, oil will float on top of water.