class 9 chapter -4 the structure of atom practice sheet

 

                                                                                                                                                   

CLASS: IX; CHEMISTRY

CHAPTER-4

THE STRUCTURE OF ATOM

Q1.What do you observe when:

(a)You comb dry hair and bring the comb near small pieces of paper.

(b)Rub a glass rod with silk cloth and bring the rod near an inflated balloon.

Q2. What is static electricity?

Q3. Who discovered electrons? Give its charge and mass.

Q4. Who discovered protons? Give its charge and mass.

Q5. What are anode rays? Why are they also called canal rays?

Q6. If an atom contains one electron and one proton, will it carry any charge or not?(NCERT page 47)

Q7. With the help of a neat labelled diagram describe Thomson’s model of an atom.

(a)State two features of Thomson’s model of an atom.

(b)Why was Thomson’ model of an atom not accepted?

Q8. On the basis of Rutherford’s model of an atom, which sub atomic particle is present in the nucleus of an atom?

Q9. Why did Rutherford select a gold foil in his alpha ray scattering experiment?

Q10 What do you think would be the observation if the alpha particle scattering experiment is carried out using a foil of a metal other than gold.

Q11. Who discovered the nucleus of the atom and how?

 Q12. Illustrate Rutherford’s experiment to explain the model of an atom with the help of a diagram.

Q13. List three observations of alpha ray scattering experiment.

Q14. State conclusion drawn from each observation of this experiment.

Q15. Write Salient feature of nuclear model of an atom.

Q16. What are the limitations of Rutherford’s model of the atom.