One day Reeta went to a jeweller's shop with her mother.Her mother gave an old gold jewellery to goldsmith to polish.Next day when they brought the jewellery back,they found that there was a slight loss in its weight.Can you suggest a reason for the loss in weight ?
To polish a gold ornament, it is dipped in an acid (called Aqua Regia). The outer layer of gold dissolves in the acid and the inner shiny layer is visible. Because of loss of the upper layer of jewellery, its weight is reduced.