Why Are Transition Metals Called Transition Metals?

Colored Transition Metal Solutions
Many transition metal solutions are brightly colored. From left to right, aqueous solutions of: cobalt(II) nitrate; potassium dichromate; potassium chromate; nickel(II) chloride; copper(II) sulfate; potassium permanganate. Ben Mills

Question: Why Are Transition Metals Called Transition Metals?

Answer: Most of the elements on the Periodic Table are transition metals. These are elements that have partially filled d sublevel orbitals. Have you ever wondered why they are called transition metals? What transition are they undergoing?

The term dates back to 1921, when English chemist Charles Bury referred to a transition series of elements on the periodic table with an inner layer of electrons that was in transition between stable groups, going from a stable group of 8 to one of 18, or from a stable group of 18 to one of 32. Today these elements are also known as d block elements. The transition elements all are metals, so they are also known as transition metals.

Transition Metal Properties | List of Transition Metals