Magnetic The energy stored when repelling poles have been pushed closer together or when attracting poles have been pulled further apart. Fridge magnets, compasses, maglev trains which use ...

cells release the energy stored in their food molecules through a series of oxidation reactions. Oxidation describes a type of chemical reaction in which electrons are transferred from one ...

and when it “burns” in air – releasing that stored energy – it simply combines with oxygen to produce water again. Different types of hydrogen production are labelled by colour.