Question

when some metal are exposed to moisture, acids etc...
they
tarnish due to the formation of respective oxide
on their surface
1 what is the Process of above statement
2) HOW
to prevent above Process?
3) whether it is oxidation or reduction!​

Answer 1

1. The process is rusting which is responsible for weakening of metal bodies
2. There are many methods to prevent this process but majorly used are galvanisation, greasing, using stainless steel etc.
3. Since there is formation of metal oxide i.e. addition of oxygen, it is oxidising process