Asked by: Richard Somerville, Northamptonshire
The structure of soap molecules enables them to remove dirt with ease. They consist of a hydrocarbon chain, with a sodium or potassium atom at the end. The hydrocarbon end is attracted to oil and repels water, whereas the other end attracts water. When you wash your hands, oily dirt particles are surrounded by soap molecules with their water-loving heads facing outwards. This breaks up the dirt and lets it wash away in the water.
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Authors
Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.
