question_answer 20)

  For the ground state, the electron in the H- atom has an angular momentum = h, according to the simple Bohr model. Angular momentum is a vector and hence there will                 be infinitely many orbits with the vector pointing in all possible directions. In actuality, this is not true. (a) because Bohr model gives incorrect values of angular momentum (b) because only one of these would have a minimum energy                                        (c) angular momentum must be in the direction of spin of electron                                             (d) because electrons go around only in horizontal orbits                        

Answer:

  Simple Bohr model, infact does not give correct values of angular momentum of revolving electron. It gives only the magnitude of angular momentum, which is a vector. So the given statement in the question is not true. Choice (a) is correct