For which element is the electron configuration [Xe] 6s^2 4f^3 valid?

The electron configuration [Xe] 6s² 4f³ corresponds to the element that has a specific number of electrons filling the 4f and outer 6s orbitals. In this case, the notation indicates that after the noble gas xenon, there are two electrons in the 6s sublevel and three electrons in the 4f sublevel.

The 4f block of the periodic table consists of the lanthanide series, and the number of electrons in the 4f subshell will determine which element it corresponds to. In this scenario, with three 4f electrons, we are specifically looking at the third element in the series of lanthanides, which is praseodymium. This element is known for having the configuration of [Xe] 6s² 4f³ due to its position in the periodic table.

Understanding this configuration helps in identifying where each element will sit within its respective series and allows for an effective way to predict its chemical behavior based on electron arrangement.