Chemical Bonding

Petrol burning, a nail rusting, or a cake baking are all chemical reactions. Chemical reactions usually change substances dramatically. For example when iron rusts: Open image in new window The iron and the constituents of moist air are still in rust, but not just mixed together. They are bound strongly together by chemical bonds. A chemical reaction is no more than a rearrangement of the chemical bonds which hold the various atoms together. To understand chemical reactions, we must picture how elements bond.