An element has the valence shell electronic configuration . To which block and group of the modern p — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

The electronic configuration $[Xe] 4f^7 5d^1 6s^2$ corresponds to Gadolinium ($Gd$, $Z=64$). Because the differentiating electron (the last electron filled according to Aufbau principles, overriding exceptions) enters the 4f subshell, it is an f-block element. All f-block elements (Lanthanoids and Actinoids) are placed in Group 3 (IIIB) of the periodic table.