1272 In the Bohr model of the hydrogen atom, with which you are probably somewhat familiar from Chemistry 1A, the electron is supposed to revolve around the massive ( practically stationary ) proton in a number of different "allowed" orbits, assumed to be circular. (In the low- m In est energy state the electron is in orbit number 1, and when excited by the addition of energy it moves in some higher orbit. ) The radii of these allowed orbits are determined by two conditions: (1 ) the electrical force attracting the e to the proton, which varies as 1/r and can be represented by F = A/r, causes the acceleration of e; (2) Bohr's Ist Postulate, which says that the angular momentum of the e in the nth orbit must be n(h/21 ), where h is a constant (Planck's quantum constant ) and n is the orbit number ( an integer). Using these two facts, find the radius of the non orbit and the velocity of the e in the n't orbit, in terms of A, m (mass of electron ), n, and h. 3+1