Important Questions CBSE Class 9th : Science Year 2009
(Chemistry)

Q. 1. What is nitrogen fixation? Mention 3 ways of nitrogen fixation & chemical reactions related to this process?

Q. 2. What are the limitations of Rutherford’s model of the atom?

Q. 3. Write a short note on ‘OZONE DEPLETION’?

Q. 4. What is nucleon? An element has 4 electrons in the M shell of it atom. What is the atomic no. of the element?

Q. 5. What is biogeochemical cycle? Draw a neat diagram of carbon & nitrogen cycle in nature?

Q. 6. What are the differences between atom & ion? Give examples?

Q. 7. Describe Bohr’s model of the atom?

Q. 8. Give any 3 properties of Canal rays?

Q. 9. Define Isotopes? What are the characteristics of isotopes? Write any 4 uses of Isotope?

Q. 10. What are the fundamental particles of atom? Write their Absolute charge & Mass?

Q. 11. Which of the 2 elements would be more reactive & why,element X of atom no.36 or element Y of atomic no.20?

Q. 12. Write any 4 importance of water in plant life?

Q. 13. What is denitrification?

Q. 14. Relative atomic mass of an element A is 16.2.There are 2 isotopes with mass no.16 and 18 respectively of the element. Calculate the percentage of these 2 isotopes present in the element?

Q. 15. Write any 4 properties of cathode rays?