The radius of circular electron orbits in the Bohr model of the hydrogen atom are given by (5.29 ✕ 10−11 m)n2, where n is the electron's energy level (see figure below). The speed of the electron in each energy level is (c/137n), where c = 3 ✕ 108 m/s is the speed of light in vacuum.

(a) What is the centripetal acceleration of an electron in the ground state (n = 1)of the Bohr hydrogen atom?
magnitude( )m/s2
direction( )

(b) What are the magnitude and direction of the centripetal force acting on an electron in the ground state?
magnitude( )N
direction( )

(c) What are the magnitude and direction of the centripetal force acting on an electron in the
n = 2 excited state?
magnitude( )N
direction( )