Life Processes — Science STD 10 — Question

What happens when nitric acid is added to egg shell?

Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents like ethanol also?

List any three hazards of nuclear waste. How does the disposal of nuclear waste pose a problem for the plant and animal life?

What can you see in a completely dark room? If you switch on an electric bulb in this dark room as a light source, explain how you could now see:

1. The electric bulb.
2. A piece of white paper.

What is meant by ocean thermal energy? Explain how ocean thermal energy can be used to generate electricity.

A hard material X which is mined from the earth is used as a house hold fuel and also for the generation of electricity at Thermal Power Stations. A soft material Y is also used us a fuel in the form of candles. A gaseous material Z which occurs along with petroleum is increasingly being used as a fuel in running vehicles in its compressed form.

1. What are materials, X, Y and Z?
2. When materials X, Y and Z are burned separately:

1. When material burns by producing a yellow, luminous flame?
2. Which material ultimately burns without producing a flame?
3. Which material can burn in a gas stove by producing a blue flame?

What happens when a zinc strip is dipped into a copper sulphate solution?

1. Write the equation for the reaction that takes place.
2. Name the type of reaction involved.

A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z.

a. Name the two types of gametes produced by men.
b. Does a male child inherit X chromosome from his father? Justify.
c. How many types of gametes are produced by a human female?