Why do you feel lighter when you swim?

Why do you fall in the forward when a moving bus breaks to shop and backwards when it acceleration from rest.

What do you observe when you drop a piece of sodium into ethanol? Name the gas evolved. How do you test this gas? Write the chemical equation for the reaction.

When sulphuric acid is added to 1g solid sodiumchloride taken in a test tube, which gas is released? What changes do you observe when you test the gas with dry and wet litmus paper? What conclusion do you draw by this experiment?

What do you mean by latent heat of fusion?

What do you mean by biosphere?

Why do you think the zygote is dormant for sometime in a fertilized ovule?