Question

What is corrosion$?$ What are the necessary conditions for corrosion$?$

Answer 1

Hint: Corrosion is the phenomenon of forming a layer of oxide on the metal surface. It may vary from metal to metal. The strength of metal decreases rapidly as the metal is converted into its oxide. In Spite of that the conditions of corrosion are common for almost all metals.

Complete answer:
Corrosion is the eating of metals when it comes in contact with air, water, electric charge and other environmental factors. We can also define corrosion as the eating up of the metals layer by layer from top to bottom of metal by the action of water and air present in the environment. Thus this phenomenon of eating is known as corrosion of metals. There are many conditions by which corrosion of metal takes place. Some of the necessary conditions which causes corrosion of metals are listed below:
$(i)$ Availability of moisture in the environment: This is the most necessary condition or we can say the very first reason for corrosion of metals. Moisture is due to the presence of water droplets in the air. Thus when the metal is in continuous contact of moisture for a long time then it gets corroded easily.
$(ii)$The metals which are highly reactive in nature get corroded easily. The metals which have a higher rate of activity are more vulnerable to corrosion. Thus to prevent the metal from corrosion, a higher active metal than the protected metal is placed beside it.

Note:
There are many ways through which corrosion of metals can be prevented easily. Corrosion is a general process of redox reaction. Therefore we can prevent corrosion by preventing this redox reaction from taking place. It weakens the metallic properties of the metal.