Give reasons: $Sodium$,$potassium$,and $lithium$ are stored under oil.

You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.

$A$ 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?

Which of the following methods is suitable for preventing an iron frying pan from rusting?

Give reasons: Platinum,gold,and silver are used to make jewellery.

What type of oxides are formed when non-metals combine with oxygen?