1. The phenomenon of radioactivity was discovered by ________.
2. What is the chemical symbol for gold?
3. In which year J.J.Thomson discovered the electron?
4. Who suggested first time model of atom?
5. What is the order in meter of the atomic radius?
6. What is the order of nucleus radius in meter?
7. Which phenomenon of electron emission is not explained by the J.J.Thomson 1904 Atomic Model?
8. In which year α-particle scattering was observed by the Rutherford’s experiment?
9. In the Rutherford’s α-particle scattering experiment when α-particles falls upon a photographic plate in the vacuum, a sharp image is obtained. But when a thin metal foil is placed in between the path and photographic plate, the image get diffuse. The reason of it was;
10. The name of scientist(s) who first discovered atomic nucleus in an atom by the scattering of α-particles on the gold foil are?
11. The atomic nucleus contains positive charge and further it is confined on a very small space at the center. So, on what basis Rutherford concluded it in 1911, from the α-particles scattering experiment?
12. From the α-particles scattering experiment it was observed that only 1 out of about 20,000 α-particles is scattered at an angle greater than 90,0. What from this was concluded about the nuclear size as compared to the atomic size?
13. When the α-particles passing close to the nucleus, experiences a large repulsive force and is scattered through a large angle, what type of charges assumed on the nucleus based on this observation?
14. As per the coulomb’s law, the repulsive force is inversely proportional to the square of the distance of the α-particle from the nucleus. When the α-particles passing close to the nucleus, experiences a large repulsive force and is scattered through a large angle. In 1913, Geiger and Marsden repeated this experiment and observed different values of N(no of α-particles) corresponding to different values of θ (scattering angle). Are you agree with this statement that Coulomb’s law holds for atomic distances too?
15. As the α-particle approaches the nucleus, the electrostatic repulsive force due to the nucleus increases. And the kinetic energy of the particle goes on converting into the electrostatic potential energy. this time α-particle can not go towards nucleus and return back on its own path. This minimum distance is known as “distance of closest approach”. Are you agree with this explanation?
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