Question

rancidity and corrosion

Answer 1

corrosion:-) when the surface of metal is eaten up gradually due to the moist air the surface of the metal get oxidized this phenomena is called corrosion.
Rancidity:-) the condition produced by aerial oxidation of fats and oils in food mark by unpleasant smell and taste is called rancidity.

Answer 2

corrosion- when a metal is attacked by acid, temperature,oxygen or moisture etc to form a layer of blackish, brownish or greenish colour on the top layer of the metal is called corrosion. it generally occurs in every metal. Ex- silver

rancidity- when fats and oils present in food materials get oxidized by the oxygen, and they give unpleasant smell and taste is called rancidity
Ex- potato chips exposed for long time in air starts giving unpleasant smell and taste.

hope it helps:)