Which compound shows both acidic and basic properties (amphoteric)?

What happens when dilute hydrochloric acid is added to iron fillings ?

Noise is measured in –

What is the boiling point of water at sea level?

The primary function of bile in digestion is to:

Which one of the following statement regarding the sun is correct? 

The frequency range of human hearing is approximately:

Which of the following is most correct about a balanced diet?

Lakes freeze in cold countries in winter, leaving the water underneath at –