Quantum mechanical model

• Erwin Schrödinger


  Develop the quantum mechanical model, describing the elements as existing in probabilistic clouds (orbitals) rather than fixed orbits
• Werner Heisenberg


  Introduce the uncertainty principle, stating that it is impossible to know both the position and momentum of an electron simultaneously
• James Chadwick


  Discovered the neutron, completing the picture of the atomics basic subatomic structure