If this seems like a homework question please forgive me, but it is merely for understanding and confidence building. I've been reading into the Bohr Model and the Wave Mechanics Model and I read through de Broglie and have proceeded to Schrodinger, Heisenberg and Dirac. At this stage, my mind is fried but can someone please confirm if I have understood their contributions correctly? Schrodinger suggested the existence of orbitals as opposed to orbits. Heisenberg suggested that electron vibration is driven more by the wave nature than the particle nature and that we cannot determine the position of an electron based on momentum as momentum is not associated with electron position. Instead we can statistically estimate where the electron can be 95% of the time. Dirac proposed the 1/2 spins and the -1/2 spins to illustrate the opposite spins of electrons which we come to accept in Pauli's exclusion principle?