What is the difference between an orbit in Bohr's model of the atom and an orbital in the quantum mechanical view of the atom?
The Bohr model assumed that electrons orbit the atom like planets orbiting the sun
The quantum mechanical view of the atom talks about wave functions and the probability of finding an electron at various places around the atom. With the quantum mechanical model, orbitals can be different shapes (eg, S - spherical, P - dumbbell). The Bohr model still serves some purposes but it is overly simplistic.