If you get a puncture on the road it's far easier to change the tube and repair the punctured one later at home. To repair the tube you'll need a pump, tyre levers and a puncture repair kit with patches, sandpaper, a marker and glue. 2. Stand the bike upside down.
Chemical reaction. A process in which one or more substances (reactants) are chemically changed into one or more new substances (products). Chemical changes may involve motion of electrons in the forming and breaking of chemical bonds.
A rearrangement of the atoms or molecules of two or more substances that come into contact with each other, resulting in the formation of one or more new substances. 1  Chemical reactions are caused by electrons of one substance interacting with those of another. The reaction of an acid with a base, for example, results in the creation of a salt and water. Some, but not all, reactions can be reversed. See nuclear reaction.