Coulomb's Law

The Electronic Structure activity Part I use Coulomb’s law model and ionization energy to invent a shell model for electrons in an atom. Based on the ionization energy data and Coulomb’s law student interpret the energy of electrons in terms of shells. The Electronic Structure activity Part II use photoelectron spectroscopy to understand that electrons in shells do not all have the same energy. So the concept of a subshell can be introduced to understand the different energies electrons have in a particular shell.

With the knowledge that electrons can occupy shells and subshells, electron configurations can be used as a notation to represent the energy of all of the electrons in an atom. Students are then prepared to explain the periodic property of ionization energy and atomic radii.

Another important concept that comes out of The Electronic Structure activity Part I is that the energy of the electron in an atom has a negative sign, and that the energy of an electron in shells of larger n values increases, which results in the energy to remove/ionize the electron decreases. The Bohr model of the atom does has its usefulness for students at the introductory level.

I believe this approach to introducing the electronic structure is much more understandable compared to emission spectra of hydrogen atoms.

Coulomb’s law appears in seven different Essential Knowledge statements (1.B.1, 1.B.2, 1.C.1, 1.C.2, 2.C, 2.C.1 and 2.C.2) in the Curriculum Framework, three different LOs (1.7, 1.8 and 2.14) and one Science Practice (SP3).