Imagine that one day the water on the whole earth disappeared. Give some consequences that we would face.

Smoking is injurious to health'. This is the slogan seen in all cigarette packets. a. As said above "is smoking injurious to health? b. Name the toxic alkaloid seen in it. c. Give some consequences a smoker has to face in the future.

What would happen , if the force of gravity disappears suddenly on Earth ?

If the distance between the Earth and Sun were to be doubled from its present value, the number of days in a year would be

Now-a-days cancer-death is increasing day by day. Is this due to the change in living habits? a. What do you think about this statement? b. Give some characters of this disease. c . It is found out that mutations in some genes cause cancer. Justify this statement.

When tertiary butyl alcohol and 1-butanol are separately treated with a few drops of KMnO_(4) , in one case only the purple colour disappears and a brown precipitate is formed. Which of the two alcohols gives the above reaction and what is that brown precipitate.

Some scientists have predicted that a global nuclear war on the earth would be followed by a severe 'nuclear winter' with a devastating effect on life on earth. What might be the basis of this prediction ?