It was Paheli's birthday. Her grandmother gave her two gifts made of metals one old dull silver spoon and a pair of lustrous gold earrings. She was surprised to see the difference in the appearance of the two metals. Can you explain the reason for this difference?

The silver spoon appeared dull because:

i. It was old, and it must have been exposed to air for a long time.

ii. When silver is exposed to air, it reacts with sulphur present in the air and forms a dull black coat of silver sulphide.

Talking about the lustrous gold earrings:

i. Gold is considered to be a noble metal i.e. it is not very reactive.

ii. It is found at the end of the metal activity series indicating it’s lack of activity.

iii. Since it doesn't react, no coat is formed over it, though over time, gold may lose its shine. The shine again can be restored by polishing it.