What is the corrosion of iron known as?

46 What is corrosion ? 46 Name any two metals which do not corrode easily. 46 Explain why, aluminium is a highly reactive metal, still it is used to make utensils for cooking. 47 What is meant by 'rusting of iron'? With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.