# What are the electron configurations for the f-block elements?

Jun 30, 2017

There is not much of a pattern. You'll just have to look and see... For the lanthanides...

$\text{La} : \left[X e\right] 6 {s}^{2} 5 {d}^{1}$

$\text{Ce} : \left[X e\right] 6 {s}^{2} 4 {f}^{1} 5 {d}^{1}$

$\textcolor{g r e e n}{\text{Pr} : \left[X e\right] 6 {s}^{2} 4 {f}^{3} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Nd} : \left[X e\right] 6 {s}^{2} 4 {f}^{4} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Pm} : \left[X e\right] 6 {s}^{2} 4 {f}^{5} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Sm} : \left[X e\right] 6 {s}^{2} 4 {f}^{6} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Eu} : \left[X e\right] 6 {s}^{2} 4 {f}^{7} 5 {d}^{0}}$

$\text{Gd} : \left[X e\right] 6 {s}^{2} 4 {f}^{7} 5 {d}^{1}$

$\textcolor{g r e e n}{\text{Tb} : \left[X e\right] 6 {s}^{2} 4 {f}^{9} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Dy} : \left[X e\right] 6 {s}^{2} 4 {f}^{10} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Ho} : \left[X e\right] 6 {s}^{2} 4 {f}^{11} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Er} : \left[X e\right] 6 {s}^{2} 4 {f}^{12} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Tm} : \left[X e\right] 6 {s}^{2} 4 {f}^{13} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Yb} : \left[X e\right] 6 {s}^{2} 4 {f}^{14} 5 {d}^{0}}$

$\textcolor{g r e e n}{\text{Lu} : \left[X e\right] 6 {s}^{2} 4 {f}^{14} 5 {d}^{1}}$

The green ones are ones that follow the Aufbau Principle. And for the actinides:

$\text{Ac} : \left[R n\right] 7 {s}^{2} 6 {d}^{1}$

$\text{Th} : \left[R n\right] 7 {s}^{2} 6 {d}^{2}$

$\text{Pa} : \left[R n\right] 7 {s}^{2} 5 {f}^{2} 6 {d}^{1}$

$\text{U} : \left[R n\right] 7 {s}^{2} 5 {f}^{3} 6 {d}^{1}$

$\text{Np} : \left[R n\right] 7 {s}^{2} 5 {f}^{4} 6 {d}^{1}$

$\textcolor{g r e e n}{\text{Pu} : \left[R n\right] 7 {s}^{2} 5 {f}^{6} 6 {d}^{0}}$

$\textcolor{g r e e n}{\text{Am} : \left[R n\right] 7 {s}^{2} 5 {f}^{7} 6 {d}^{0}}$

$\text{Cm} : \left[R n\right] 7 {s}^{2} 5 {f}^{7} 6 {d}^{1}$

$\textcolor{g r e e n}{\text{Bk} : \left[R n\right] 7 {s}^{2} 5 {f}^{9} 6 {d}^{0}}$

$\textcolor{g r e e n}{\text{Cf} : \left[R n\right] 7 {s}^{2} 5 {f}^{10} 6 {d}^{0}}$

$\textcolor{g r e e n}{\text{Es} : \left[R n\right] 7 {s}^{2} 5 {f}^{11} 6 {d}^{0}}$

$\textcolor{g r e e n}{\text{Fm} : \left[R n\right] 7 {s}^{2} 5 {f}^{12} 6 {d}^{0}}$

$\textcolor{g r e e n}{\text{Md} : \left[R n\right] 7 {s}^{2} 5 {f}^{13} 6 {d}^{0}}$

$\textcolor{g r e e n}{\text{No} : \left[R n\right] 7 {s}^{2} 5 {f}^{14} 6 {d}^{0}}$

$\textcolor{g r e e n}{\text{Lr} : \left[R n\right] 7 {s}^{2} 5 {f}^{14} 6 {d}^{1}}$

Again, the green ones are the normal ones. You obviously don't have to memorize these.