Sodium (Na) has the same electron configuration as Lithium (Li) in its ground state.

Here's why:

* Electron Configuration of Sodium (Na): 1s² 2s² 2p⁶ 3s¹

* Electron Configuration of Lithium (Li): 1s² 2s¹

Both elements have one valence electron in their outermost shell (3s¹ for sodium and 2s¹ for lithium). This similarity in their electron configuration is why they share similar chemical properties, placing them in the same group (Group 1, Alkali Metals) of the periodic table.