Which element has the configuration [Rn] 7s^2 5f^14 6d^4?

The electron configuration [Rn] 7s^2 5f^14 6d^4 corresponds to the element Seaborgium. This is because the configuration indicates that Seaborgium, which is a transactinide element, has filled 5f orbitals (14 electrons) and partially filled 6d orbitals (4 electrons), following the stable core of Radon (Rn).

In this configuration, the presence of the 7s^2 indicates that two electrons occupy the 7s subshell, characteristic of elements in the seventh period of the periodic table. The filled 5f subshell suggests that the element is well into the actinide series, which includes heavy elements. The additional four electrons in the 6d subshell indicate a progression into the d-block of the periodic table for this heavy element.

In contrast, Mendelevium, Curium, and Plutonium possess different electron configurations, primarily found in earlier periods of the actinides and exhibit different filling patterns in the f and d orbitals. Mendelevium and Curium, for example, have fewer f electrons and do not reach the 6d subshell in their configurations. Thus, Seaborg