D -Transition elements
Definition and meaning of D -Transition elements in chemistry.
D -Transition elements are the chemical elements found in the d-block of the periodic table, encompassing groups 3 through 12, characterized by having partially filled d subshells in their elemental state or common oxidation states. They are widely known for their metallic properties, catalytic abilities, and tendency to form highly colored coordination compounds.
In more detail
These metals display a wide variety of oxidation states because the energy difference between the ns and (n-1)d orbitals is relatively small, allowing electrons from both subshells to participate in chemical bonding. As a result, transition elements readily form complex ions with various ligands. Their partially filled d orbitals also facilitate electronic transitions that absorb specific wavelengths of visible light, which gives their compounds distinctive colors. Furthermore, their ability to easily adopt multiple oxidation states makes them excellent industrial and biological catalysts.
Key facts
| Field | Inorganic Chemistry |
|---|---|
| Location | d-block of periodic table |
| Characteristic | Variable oxidation states |
Iron (Fe) is a quintessential d-transition element that forms both Fe2+ and Fe3+ ions and serves as the active catalytic center in hemoglobin.
Frequently asked questions
Why do transition metals form colored compounds?
The splitting of d orbitals allows electrons to absorb visible light during transitions.
Are all d-block elements transition metals?
Zinc, cadmium, and mercury are sometimes excluded because they have full d subshells.