State two ways to prevent the rusting of iron.
Why do ionic compounds have high melting points ?
Define the following terms.
$(i)$ Mineral $(ii)$ Ore $(iii)$ Gangue
Give reasons : Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?