Question

take a aluminium wire and rub it using a sandpaper you can see a bright metallic lustre, within a few days it gets tarnished why does it happen?​

Answer 1

Answer:

The surface of the metal gets tarnished. This is due the reaction with the air. When metals come in contact with the atmosphere, they undergo chemical reaction because air contains different components and metals react with them and eventually loose their metallic lustre and gets tarnished.