Atomic Physics Nuclear Physics and Radioactivity Example Problems with Solutions.pdf - Atomic Physics Nuclear Physics and Radioactivity Example Problems

Atomic Physics Nuclear Physics and Radioactivity Example Problems with Solutions.pdf

This preview shows page 1 - 3 out of 6 pages.

1 Atomic Physics, Nuclear Physics and Radioactivity: Example Problems with Solutions ATOMIS PHYSICS DISCOVERY OF THE PARTS OF THE ATOM: ELECTRONS AND NUCLEI 1. Rutherford found the size of the nucleus to be about . This implied a huge density. What would this density be for gold? Nucleus diameter = 10 -15 m Gold mass = 197 amu 1 amu = 1.66 x 10 -27 kg Solution 2. In Millikan’s oil -drop experiment, one looks at a small oil drop held motionless between two plates. Take the voltage between the plates to be 2033 V, and the plate separation to be 2.00 cm. The oil drop (of density ) has a diameter of . Find the charge on the drop, in terms of electron units. Solution m 10 15 3 g/cm 0.81 m 10 0 . 4 6   16 n C 10 1.6 C 10 2.6 e q n C 10 2.6 q V 2033 m 10 2 m/s 9.8 kg 10 2.71 q V d g m q g m d V q W F kg 10 2.71 m 6 m 10 4.0 π kg/m 810 m d π 6 1 ρ m 8 d π 3 4 ρ 2 d π 3 4 ρ r π 3 4 ρ ρV m g m W d V E ; E q F electrons -19 -18 electrons -18 2 - 2 -14 e -14 3 6 - 3 3 3 3 drop oil 3 e drop oil 3 20 3 46 - 25 - 3 -16 25 - 3 -16 -25 -27 kg/m 10 6.5 ρ m 10 5 kg 10 3.27 ρ m 10 5 3 4 kg 10 3.27 ρ r 3 4 m ρ V m ρ ρV m m 10 5 r kg 10 3.27 m kg/amu 10 1.66 amu 197 m