9th science december

9th class science paper

1. AD PUBLIC SR SEC SCHOOL CHANDHUT
SUBJECT :- SCIENCE CLASS :- 9
th
MM :- 60
1. What is meant by a pure substance ? (2)
2. State any two conditions essential for good health . (2)
3. Define the term “tissue” . (2)
4. If an atom has 8 protons and 10 neutrons .Find atomic number and mass number of
atom . (2)
5. Explain any one method of crop production which ensures high yield . (2)
6. What are the functions of stomata ? (2)
7. What are the advantages of classifying organisms ? (2)
8. What are differences between amphibians and reptiles ? (2)
9. What are the constituents of the phloem ? (2)
10. Define molecular mass ? (2)
11. Why are we normally advised to take bland and nourishing food when we are sick ? (2)
12. What is the green house effect ? (2)
13. Which of the following materials fall in the category of a “pure substance”? (a)ice
(b)milk (c)iron (d)mercury (e)brick (f) wood (2)
14. Why is water essential for life ? (2)
15. 12.044×10^23 number of He atoms find the number of moles from number of particles
given Avogadro number = 6.022 ×10^23 (2)
16. List the points of differences between homogeneous and heterogeneous mixtures ?
(3)
17. Compare the use of manure and fertilizers in maintaining soil fertility ? (3)
18. Describe the Bohr’s model of atom with diagram ? (3)
19. Write the distribution of electrons in sodium atom ? (3)
20. Define atom . describe Thomson’s model of an atom . (1+2)
21. How do biotic and abiotic factors affect crop production ? (3)
22. How are clouds formed ? (3)
23. What precautions can you take in your school to reduce the incidence of infectious
diseases ?(3)
24. Calculate molecular masses of ZnO, Na2O, K2CO3 , given atomic mass of Zn=23 u ,
K=39 u , C=12 u , and O=16 u (3)
25. Classify the following into elements ,compounds,and mixtures . (a) sodium (b)soil
(c)sugar solution (d)silver (e)tin (f)silicon (g)coal (h)air (i)soap (3)