Rust is

Given below are two statements:
Statement $I$: Corrosion is an electrochemical phenomenon in which pure metal acts as an anode and impure metal as a cathode.
Statement $II$: The rate of corrosion is more in alkaline medium than in acidic medium.
In the light of the above statements,choose the correct answer from the options given below:

Why is it important to stop corrosion?

Aluminium is more reactive than $Fe$. But $Al$ is less easily corroded than iron because

To prevent corrosion,iron pipes carrying drinking water are covered with zinc. The process involved is

Which of the following statements is not correct about the rusting of iron?