Here's why:
* Water is a polar molecule: This means it has a slightly positive end and a slightly negative end due to the uneven sharing of electrons between the oxygen and hydrogen atoms.
* Oil is a non-polar molecule: Its molecules are made up of mostly carbon and hydrogen atoms, which share electrons more evenly. This results in a molecule with no distinct positive or negative ends.
Like dissolves like: Polar molecules are attracted to other polar molecules, and non-polar molecules are attracted to other non-polar molecules. Since water is polar and oil is non-polar, they don't have a strong attraction to each other. Instead, the water molecules will stick together, and the oil molecules will stick together, resulting in separation.
