Question

Assertion: We apply paint on iron articles.
Reason: Iron is metal, metals rust when they come in contact with direct air so to prevent rusting.
A.Both assertion and reason are correct and reason is the correct explanation for assertion
B.Both assertion and reason are correct and reason is not the correct explanation for assertion
C.Assertion is correct but reason is incorrect
D.Both assertion and reason are incorrect

Answer 1

Hint:Metal reacts with air or the gases present in the air and gets corroded. This happens when metal comes in the direct contact of the air or moisture. Any material that will help prevent the direct contact between the surfaces of metal the air present around will prevent the corrosion.

Complete step by step answer:
Almost all metals combine with oxygen to form metal oxide but they don't react with oxygen at the same rate. Metal such as potassium and sodium reacts very explosively with oxygen. When kept open exposed in air they even catch fire. On the other hand, metal such as silver and gold do not react with oxygen even at high temperature. The silver article turns black when exposed to air after sometime this is because they react with Sulphur present in air and not oxygen and forms silver sulphide. When a metal is attacked by a substance around it such as moisture or air then it is said to corrode and this process is called corrosion.
Examples of corrosion are rusting of iron when iron is exposed to moist air for a long time it forms a layer of brown flaky substance known as rust. Rusting of iron can be prevented by painting, greasing, and galvanization or by making alloy.

Hence option A is correct.

Note:
Galvanization is another method to prevent iron from rusting and is used very commonly. It protects steel and iron from rusting by coating them with the thin layer of Zinc. The galvanised article is protected against rusting even if the Zinc coating is broken.