Above: The four series of tranistion metals, occuring in Rows 4 through 7 of the table. Immediately below are electron shell diagrams for the first transition metal series. The common argon core for these elements is represented by the solid color in the center.

Because of the way in which the elements were synthesized (see Chapter 8), elements in the first series of transition metals are much more common than those in later series, and hence are more familiar. All of these elements are metallic solids at room temperature except mercury, which is a liquid with a freezing point of -39°C.