4. The Bohr model (Neils Bohr, 1913) treats the hydrogen atom as a minature solar system. Although the model is incorrect it provided early insight into the quantum mechanics of atoms. Assume the electron (mass m, charge -e) is in a circular orbit of radius r around the proton (charge +e, mass M). M » m so the proton is stationary. From Physics 211, a object moving in a circle at constant speed will experience a centripetal acceleration v? /r directed toward the center of the circle. Use circular motion dynamics to determine the speed of the electron in orbit. Answer in terms of r, e, m and/or M. Gravitational forces are negligible at the atomic level. a. b. What is the kinetic energy of the electron in orbit? Answer in terms of e,r and/or m.

4. The Bohr model (Neils Bohr, 1913) treats the hydrogen atom as a minature solar system. Although the model is incorrect it provided early insight into the quantum mechanics of atoms. Assume the electron (mass m, charge -e) is in a circular orbit of radius r around the proton (charge +e, mass M). M » m so the proton is stationary. From Physics 211, a object moving in a circle at constant speed will experience a centripetal acceleration v? /r directed toward the center of the circle. Use circular motion dynamics to determine the speed of the electron in orbit. Answer in terms of r, e, m and/or M. Gravitational forces are negligible at the atomic level. a. b. What is the kinetic energy of the electron in orbit? Answer in terms of e,r and/or m.