An carly modcl of the atom, proposed by Rutherford after his discovery of the atomic nucleus, had a positive point charge +Ze (the nuclcus) at the center of a sphere of radius R with uniformly distributed negative charge -Ze. Z is the atomic number, the number of protons in the nucleus and the number of clectrons in the negative sphere. (a) Show that the clectric ficld inside this atom is (÷) Ze 1 Ein 4T€0 R3 (b) What is E at the surface of the atom? Is this the expected valuc? Explain. (c) A uranium atom has Z = 92 and R = 0.10 nm. What is the clectric ficld strength at r = R? %3D

An carly modcl of the atom, proposed by Rutherford after his discovery of the atomic nucleus, had a positive point charge +Ze (the nuclcus) at the center of a sphere of radius R with uniformly distributed negative charge -Ze. Z is the atomic number, the number of protons in the nucleus and the number of clectrons in the negative sphere. (a) Show that the clectric ficld inside this atom is (÷) Ze 1 Ein 4T€0 R3 (b) What is E at the surface of the atom? Is this the expected valuc? Explain. (c) A uranium atom has Z = 92 and R = 0.10 nm. What is the clectric ficld strength at r = R? %3D