What is the Difference Between First Second and Third Transition Series?

The difference between the first, second, and third transition series lies in the electron configuration, atomic radius, and stability in higher oxidation states. Here are the key differences:

1. Electron configuration: The first transition series has the outermost d orbital as 3d, the second series has 4d, and the third series has 5d.
2. Atomic radius: In general, the atomic radius increases down a group, which leads to the ions of the second and third series being larger than those in the first series.
3. Stability in higher oxidation states: The elements of the second and third transition series are generally more stable in higher oxidation states than the elements of the first series.

The first transition series includes elements from scandium (Sc) to copper (Cu), the second series from yttrium (Y) to silver (Ag), and the third series from lanthanum (La) to mercury (Hg). Transition elements in the third series typically have a complete Xenon electron configuration with 5d.

Comparative Table: First Second vs Third Transition Series

The main difference between the first, second, and third transition series lies in the electron configuration and the outermost d orbitals of the elements in each series. Here is a comparison of the three transition series:

The first transition series includes elements from Scandium (Sc) to Copper (Cu), and their highest oxidation states range from +3 to +2 depending on the specific element. The second transition series consists of elements from Yttrium (Y) to Silver (Ag), with their highest oxidation states generally being +4 for the early elements (Zr, Hf) and +3 for the later elements (Ru, Rh, Pd). The third transition series, also known as the lanthanide series, includes elements from Lanthanum (La) to Gold (Au), and their highest oxidation states are +4 for the lanthanide elements and +4 for Gold.