Question

Some articles made of silver copper and iron gate coating over with them when they are exposed to air

Answer 1

Some articles made of silver copper and iron gate coating over with them when they are exposed to air, this is because of corrosion when silver reacts with Sulphur and forms Silver Sulphide.

Copper forms Copper oxide and gives a green color.

Answer 2

HIII....

HERE IS YOUR ANSWER:--------

SOME ARTICLES MADE OF SILVER COPPER AND IRON GATE COATING OVER WITH THEM WHEN THEY ARE EXPOSED TO AIR,THIS IS BECAUSE OF CORROSION WHEN SILVER REACTS WITH SULPHUR AND FORMS SULPHIDE.

HOPE THIS HELPS YOU....