This equation, in turn, allows one to relate the kinetic energy 1/2 me v to the Coulombic energy Zer, and thus to express the total energy e of an orbit in terms of the radius of the orbit E=1/2mv2-Ze2/r=-1/2Ze2/r The energy characterizing an orbit or radius r, relative to the e=0 reference of energy at r->00, becomes more and more negative (i. e, lower and lower ) as r becomes smaller. This relationship between outward and inward forces allows one to conclude that the electron should move faster as it moves closer to the nucleus since v2=Ze/(rm) However, nowhere in this model is a concept that relates to the experimental fact that each atom emits only certain kinds of photons. It was believed that photon emission occurred when an electron moving in a larger circular orbit lost energy and moved to a smaller circular orbit. However, the Newtonian dynamics that produced the above equation would allow orbits of any radius, and hence any energy, to be followed. Thus, it would appear that the electron should be able to emit photons of any energy as it moved from orbit to orbit The breakthrough that allowed scientists such as Niels Bohr to apply the circular orbit model to the observed spectral data involved first introducing the idea that the electron has a wavelength and that this wavelength 2 is related to its momentum by the de broglie equation 2 =h/p. The key step in the bohr model was to also specify that the radius of the circular orbit be such that the circumference of the circle 2t r equal an integer(n) multiple of the wavelength 2. Only in this way will the electron's wave7 This equation, in turn, allows one to relate the kinetic energy 1/2 me v2 to the Coulombic energy Ze2 /r, and thus to express the total energy E of an orbit in terms of the radius of the orbit: E = 1/2 me v2 – Ze2 /r = -1/2 Ze2 /r. The energy characterizing an orbit or radius r, relative to the E = 0 reference of energy at r ® ¥, becomes more and more negative (i.e., lower and lower) as r becomes smaller. This relationship between outward and inward forces allows one to conclude that the electron should move faster as it moves closer to the nucleus since v2 = Ze2 /(r me ). However, nowhere in this model is a concept that relates to the experimental fact that each atom emits only certain kinds of photons. It was believed that photon emission occurred when an electron moving in a larger circular orbit lost energy and moved to a smaller circular orbit. However, the Newtonian dynamics that produced the above equation would allow orbits of any radius, and hence any energy, to be followed. Thus, it would appear that the electron should be able to emit photons of any energy as it moved from orbit to orbit. The breakthrough that allowed scientists such as Niels Bohr to apply the circular￾orbit model to the observed spectral data involved first introducing the idea that the electron has a wavelength and that this wavelength l is related to its momentum by the de Broglie equation l = h/p. The key step in the Bohr model was to also specify that the radius of the circular orbit be such that the circumference of the circle 2p r equal an integer (n) multiple of the wavelength l. Only in this way will the electron’s wave