<Li> 1922--Otto Stern and Walther Gerlach perform the Stern--Gerlach experiment, which detects discrete values of angular momentum for atoms in the ground state passing through an inhomogeneous magnetic field leading to the discovery of the spin of the electron . </Li> <Li> 1922--Bohr updates his model of the atom to better explain the properties of the periodic table by assuming that certain numbers of electrons (for example 2, 8 and 18) corresponded to stable "closed shells", presaging orbital theory . </Li> <Li> 1923--Pierre Auger discovers the Auger effect, where filling the inner - shell vacancy of an atom is accompanied by the emission of an electron from the same atom . </Li> <Li> 1923--Louis de Broglie extends wave--particle duality to particles, postulating that electrons in motion are associated with waves . He predicts that the wavelengths are given by Planck's constant h divided by the momentum of the mv = p of the electron: λ = h / mv = h / p . </Li>

Who were the two scientist given the credit for quantum mechanics