Resumen de Housing Electrons:: Relating Quantum Numbers, Energy Levels, and Electron Configuration
In the quantum mechanical model of the atom, quantum numbers are associated with individual electrons in an atom so that each electron in its ground state is assigned a set of four quantum numbers. Quantum mechanics deals only with the probability of finding an electron within a given region of space outside of the nucleus. The arrangement of electrons among the various probability locations of an atom is called the electron configuration of the atom. Students learn that these probability locations are also related to the energy level of each electron.
Confusion is often generated as students attempt to relate quantum numbers to these probability locations, electron configurations, and energy levels. This paper attempts to combine these three concepts in a concrete, hands-on way for students. Four model houses are constructed and divided into levels and rooms within those levels. Each house represents the primary quantum number (n), each floor represents the second quantum number (l) or sublevel, and each room represents the third quantum number (ml) or orbital. Different colored beads are used to represent the electrons with opposite spins, thus introducing the forth quantum number (ms).
Key to the analogy is the mounting of the four houses on a section of pegboard with each house placed at a different level on the "energy level hillside" so that the levels of the floors correspond to the energy levels of the sublevels presented by the energy level diagrams typical of most texts discussing this topic. When the levels are properly arranged, the rooms of the houses, which correspond to orbitals, should align as do the boxes on an Aufbau diagram. A hillside painted on the pegboard enhances the analogy. Students relate the model analogy very well.
