Our government launches campaigns to provide information about AIDS prevention, testing, and treatment by putting posters, conducting radio shows and using other agencies of advertisements.

a) To which category of diseases AIDS belong? Name its causative organism.

b) Which kind of value is the government trying to develop in the citizens by conducting the above kind of programs?

A compound which is prepared from gypsum has the property of hardening when mixed with a proper quantity of water. Identify the compound and write its chemical formula. Write the chemical equation for its preparation. Mention any one use of the compound.

Why are fossils considered important in the study of evolution? Explain two ways by which age of fossils can be estimated.

With the help of a labelled circuit diagram wire describe an activity to illustrate the pattern of the magnetic field lines around a straight current carrying long conducting wire.

i) Name the rule that is used to find the direction of the magnetic field associated with a current carrying conductor.

ii) Is there a similar magnetic field produced around a thin beam of moving (a) alpha particles and (b) neutrons? Justify your answer.

You are given balls and stick model of six carbon atoms and fourteen hydrogen atoms and sufficient number of sticks. In how many ways one can join the models of six carbon atoms and fourteen hydrogen atoms to form different molecules of C₆H₁₄.