VERY SHORT ANSWER TYPE QUESTIONS
Q. 1. Write the names of two natural substances.
Ans. (i) Air (ii) Water
Q. 2. Name two man-made substances.
Ans. (i) Car (ii) Bus
Q. 3. Name two natural resources.
Ans. (i) Air (ii) Water
Q. 4. Write two exhaustible substances.
Ans. (i) Coal (ii) Natural gas
Q. 5. Why are air, water and soil called natural resources?
Ans. Air, water and soil are provided by nature so they are called natural resources.
Q. 6. Name any two inexhaustible natural resources.
Ans. (i) Air (ii) Sunlight
Q. 7. Why are Coal, Petroleum and Natural gas called fossil fuels?
Ans. Coal, Petroleum and Natural gas are formed by fossils, so they are called fossil fuels.
Q. 8. Which gas is produced when coal burns in air?
Ans. Carbon dioxide.
Q. 9. Name the gas which is formed when coal is heated in the absence of air.
Ans. Coal gas.
Q . 10. What is the purest form of carbon?
Q . 11. What is the main use of coke?
Ans. It is used in the extraction of metals.
Q . 12. How many substances are found in coal tar?
Ans. About 200 substances.
Q . 13. Name the substance obtained from the coal tar and used to repel moths and insects.
Ans. Naphthalene balls.
Q . 14. Which substance is used for road surfacing these days?
Ans. These days bitumen is used for road surfacing in place of coal tar.
Q . 15. Where was the first oil well drilled?
Ans. The first oil well was drilled at Pennsylvania, USA, in 1859.
Q . 16. Where and when was the first oil well drilled in India?
Ans. In 1867, at Makum in Assam.
Q . 17. Name two fractions of petroleum which are used as fuel.
Ans. (i) Petrol (ii) Diesel
Q . 18. What are Petrochemicals?
Ans. The useful substances formed from natural gas and petroleum are called petro- chemicals.
Q . 19. Why is petroleum called black gold?
Ans. Due to its great commercial importance, petroleum is also called black gold.
Q . 20. Name the places where natural gas is found in our country.
Ans. Tripura, Rajasthan, Maharashtra and in the Krishna Godavari delta.
Q . 21. Expand PCRA.
Ans. Petroleum Conservation Research Association.
Q . 22. Can we use all our natural resources forever?
Ans. No, we cannot use all our natural resources forever, because these are going to exhaust one day.
Q . 23. Can air, water and soil be exhausted by human activities?
Ans. No, these cannot be exhausted at all.
Q . 24. Is water a limitless source?
Ans. Yes, water is a limitless source, but by unwise use and cutting of trees, sources of water can be finished.