Friday, June 15, 2012

8th Biology CBSE Test paper : METALS AND NON- METALS


NOTE— to 16 carry two marks to 25 carry three marks each.

Q.1. Differentiate between minerals and ores.

Q.2. What are metalloids? Give some examples.

Q.3. What do you mean by Reactivity and Reactivity Series.

Q.4. What is a displacement reaction? Give an example.

Q.5. What happens when Mg ribbon is put into CuSO4 soluition? Write the balanced chemical equation also.

Q.6. Why is pure gold not suitable for making jewellery?

Q.7. Why is iron metal known as the backbone of the industry ?

Q.8. Why is Ag metal not used for making electrical wires?

Q.9. Why is aluminium foil used to wrap food items?

Q.10. Why are immersion rods for heating liquids are made up of metallic substances?

Q.11. Write some common uses of Cu metal.

Q.12. What will happen when we put Cu rod in ZnSO4 solution? Give suitable reason.

Q.13. Can you store lemon pickle in an aluminium utensil? Explain.

Q.14. Suhaani took a piece of burning charcoal and collected the gas evolved in the test tube.

(a) How will she find the nature of the gas?

(b) Write down the word equations of all the reactions taking place in this process.

Q.15. How is Carboxy Haemoglobin harmful to humans?

Q.16. What are the harmful effects of CFCs?

Q.17. Define the following terms—malleability , ductility ,sonorosity.

Q.18. How will you show that magnesium oxide is basic in nature?

Q.19. Write two uses each of the following metals--- Au ,Ag ,Pt.

Q.20. Write some common uses of non-metals.

Q.21. What are the harmful effects of nitrogen dioxide? How is it produced in the atmosphere?

Q.22. What is Global Warming? What are its harmful effects?

Q.23. How is Carbon Monoxide produced? How does it affect the growth of plants?

Q.22. Why is greenhouse effect named so?

Q.23. What are the consequences of acid rain?

Q.24. How does CO2 content rise in the atmosphere and become excessive?

Q.25. What is marble cancer? Explain it by giving a suitable example.

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