1. Name the type of compounds which are used as refrigerants and in fire extinguishers and deplete the ozone layer in the atmosphere
2. Producers always occupy the first trophic level in any food chain. Why ?
3. Write the value of near and far point of distinct vision for normal eye.
4. Draw the structure of Ethanol (C2H5OH)
5. Pre - natal sex determination has been prohibited by law. State two reasons.
6. What is placenta ? State its any two roles during pregnancy.
7. List any four stakeholders which may help in the conservation of forests
8. (a) Why are coal and petroleum called fossil fuels ?
(b) Name any two elements present in fossil fuels in addition to carbon.
9. The refractive indices of alcohol and turpentine oil with respect to air are 1.36 and 1.47 respectively. Find the refractive index of turpentine oil with respect to alcohol. Which one of these will permit the light to travel faster ?
10. Why do we observe difference in colours of the Sun during sunrise, sunset and noon ?
11. Describe the formation of rainbow in the sky with the help of a diagram.
12. State the positions of (i) isotopes of the same element and (ii) hydrogen in the modern periodic table.
13. How does the tendency to gain electrons change as we go down the 16th group of periodic table ? Why ?
No comments:
Post a Comment