What element is represented by the electron configuration [Rn] 7s² 5f¹⁴?

The electron configuration [Rn] 7s² 5f¹⁴ corresponds to an element in the actinides series, where the presence of the 5f sublevel being fully filled (5f¹⁴) indicates that this element is indeed part of the inner transition metals. The radon (Rn) notation represents the filled electron shells up to radon, which has 86 electrons, and adding the additional electrons to the 7s and 5f subshells highlights the position of the element in question.

Nobelium has an atomic number of 102, which falls into this range due to its 102 total electrons: 86 from Rn, 2 from the 7s subshell, and 14 from the fully filled 5f subshell. The configuration thus reflects the correct placement of Nobelium in the periodic table, where it is identified as element 102, conforming to its known electron configuration.

The other substances listed have electron configurations that do not match; they possess fewer or different electron distributions based on their respective atomic numbers. Therefore, the designation of Nobelium as the element represented by the provided electron configuration is accurate and consistent with periodic trends.