Class – IX
Subject – Structure of Atom
1 Marks Questions
Q1. In television picture tube which type of rays are used?
Q2. Which is heavier, neutron or proton?
Q3. If electrons move from K to L shell, will the energy be absorbed or evolved?
Q4. Helium atom has an atomic mass of 4u and two protons in its nucleus. How
many neutrons does it have?
2 Marks Questions
Q5. An ion X 2+ contains 18 electrons and 20 neutrons. Calculate the atomic
number and mass no. of element X. Name the element X.
Q7. In a given electric field, β- particles are deflected more than α- particles
inspite of the fact that α - particles have larger charge, why?
Q8. Give one Achievement and one limitation of J.J Thomson’s model of atom?
3 Marks Questions
Q9. What are valence electrons? What is their significance?
Q10. What would be the observation if the α - particle scattering experiment is
carried out using a foil of a metal other than gold?
Q11. Electronic configuration of Potassium is 2,8,8,1 and Calcium 2,8,8,2, when
M shell can have maximum of 18 electrons then why next element Scandium has
electronic configuration 2,8,9,2 and not 2,8,8,3 ?
Q12.What are isotopes and Isobars? What are two isotopes of chlorine?Calculate
the average atomic mass of a chlorine atom?
5 Marks Questions
Q13. What is present concept of an atom? Explain in detail? Why this model is
considered to be the most appropriate model?
Q14. Explain the Rutherford’s alpha particle scattering experiment. What were
the main conclusions drawn from this experiment?
Contributed By: Jsunil