Abstract
<jats:p>This study proposes a new electron configuration model to clarify the periodicity of electron configurations of all elements, including transition elements. The model reexamines electron configurations while retaining the basic concept that electrons are assigned according to energy-level relationships and that electron shells become stabilized when their electron capacities are filled. The proposed model shows that the electron configurations of all elements from Periods 1 to 7 can be consistently described by inferring that the K shell contains three types of orbitals, and that the corresponding orbital structure of the other electron shells can be inferred from the periodicity observed in the electron configurations. In this model, the three orbitals within each shell are denoted by the subscripts x, y, and z for convenience.</jats:p>