Using synchrotron infrared light and near-infrared/visible lasers without applying a magnetic field, we observed the response of valence electrons in the (C₂H₅)(CH₃)₃As[Pd(C₃S₅ ...

Elements in the same horizontal row are in the same period. The periods are numbered from top to bottom. The period number is the same as the number of occupied electron shells.

Elements in group 1 and group 2 are metals. Atoms of group 1 elements have one electron in their outer shell, and atoms of group 2 elements have two electrons in their outer shell. Elements in ...