In the the Bohr model of the atom, electrons travel in circular orbits around a positively charged nucleus in a manner similar to that of our solar system. The electrostatic force provides the attraction, rather than gravity. Furthermore, the orbits are quantized, meaning that only certain orbit are possible. In the case of the hydrogen atom, the electron orbits a proton. The smallest possible orbital radius of the Bohr atom is 0.0529nm, and is called the Bohr radius. How much energy is required to cause the atom to jump to an orbit n= 2 times the Bohr radius? Note that this problem is similar to those in chapter 13 (the chapter on gravitation). The correct result that takes quantum effects into account is 13.6eV(1-1/n 2)