+2 | +3 | +4 | |
---|---|---|---|
Eu | \(4f^7\) | \(4f^6\) | |
Tm | \(4f^{13}\) | \(4f^{12}\) | |
Sm | \(4f^6\) | \(4f^5\) | |
Tb | \(4f^9\) | \(4f^8\) | \(4f^7\) |
Yb | \(4f^{14}\) | \(4f^{13}\) | |
Dy | \(4f^{10}\) | \(4f^9\) |
Hence, the pair \(Tb^{+4} Yb^{+2}\) have half filled and completely filled \(f\) subshells respectively.
The portion of the line \( 4x + 5y = 20 \) in the first quadrant is trisected by the lines \( L_1 \) and \( L_2 \) passing through the origin. The tangent of an angle between the lines \( L_1 \) and \( L_2 \) is:
Lanthanoids are at the top of these two-row, while actinoids are at the bottom row.
Lanthanoids are inclusive of 14 elements, with atomic numbers 58-71:
These elements are also called rare earth elements. They are found naturally on the earth, and they're all radioactively stable except promethium, which is radioactive. A trend is one of the interesting properties of the lanthanoid elements, called lanthanide contraction.