9. Elaborate why materials have tendency to be corroded? Solution You understand that corrosion means oxidation in a generalized way. Means pure metals gets converted into its oxide or sulfide forms depending on in which environment they are kept. For example, iron converted to iron oxide when comes in contact with oxygen or water or silver corrodes when comes in contact with atmospheric oxygen. So why do metals have tendency to be corroded ? There are several reasons for that as follows: 1. Pure materials are most likely unstable so they will try to regain their original state that is oxides. so they will react with atmospheric oxygen or with water or with any other possible medium which will come in contact with them. As atmosphere contain oxygen and moisture (which is water) metals tends to react with them and forms oxides. (if metals are kept in pure vacuum the metals will remain in their pure form and they are less likely to corrode) 2. Another scenario will be when metals are in excited form by some kind of energy excitation. The most common example of this will be old car batteries in which two electrodes were in contact with electrolyte and current is flowing continuously through both electrodes. And the oxidation happens at Anode. 3. Then third reason would be reactivity of material with an environment. or it could be other way around if an environment reactive then it will react with metal..