Work
Tony Sanchez
periodicity
the quality or character of being periodic; the tendency to recur at intervals.
Semiconductor
A semiconductor is a material which has electrical conductivity to a degree between that of a conductor (such as copper) and that of an insulator (such as glass).
Transition Element
any of the set of metallic elements occupying a central block (Groups IVB–VIII, IB, and IIB, or 4–12) in the periodic table, e.g., iron, manganese, chromium, and copper. Chemically they show variable valence and a strong tendency to form coordination compounds, and many of their compounds are colored.