Identify the element with the electron configuration [Rn] 7s^2 5f^14 6d^7.

The given electron configuration [Rn] 7s^2 5f^14 6d^7 corresponds to the element Meitnerium (Mt). The notation [Rn] indicates that the inner electrons are the same as those found in radon, which has an atomic number of 86. Following the radon core, the configuration describes additional electrons in the 7s, 5f, and 6d subshells.

To break it down, the 5f^14 indicates that all fourteen f orbitals are filled, which is characteristic of the actinide series, but in this configuration, they are filled before moving to the 6d subshell. The 6d^7 indicates that there are seven electrons in the 6d orbital, highlighting that this element is a transition metal in the seventh period.

Meitnerium has an atomic number of 109, which matches the last configuration features and represents a synthetic element categorized within the d-block of the periodic table. The arrangement aligns with the expected filling order based on the Aufbau principle, where the 6d subshell is filled after the 7s subshell and after the 5f subshell is completely filled.

This process