Question

why does gold and silver retain there Lustre​

Answer 1

Explanation:

As they are less reactive they can retain their lustre

Answer 2

Answer:

Because they are less reactive/highly unreactive (especially with oxygen and halogens.)

Explanation:

Gold and silver lie towards the bottom of the metal reactivity series. They are highly unreactive. Silver is a bit more reactive, so it sometimes oxidises. Gold however, is very soft and stable, and has to be mixed with copper or mercury to form strong alloys for use. Their high stability, and hence long lasting lustre, is also the reason why they are extensively used in jewellery industries.