Question

which is the electron configuration for lithium?\
\\(1s^2\\)\
\\(2s^3\\)\
\\(1s^22s^1\\)\
\\(1s^12s^2\\)

Explanation:

Lithium (Li) has an atomic number of 3, meaning it has 3 electrons. The electron configuration follows the Aufbau principle, filling orbitals in order (1s, 2s, etc.). The 1s orbital can hold 2 electrons, and the remaining 1 electron goes to the 2s orbital. So the electron configuration is \(1s^2 2s^1\). The first option (\(1s^2\)) is for helium (2 electrons), the second (\(2s^3\)) is invalid as s - orbitals can hold at most 2 electrons, and the fourth (\(1s^1 2s^2\)) does not follow the filling order (1s should fill before 2s completely or as per the number of electrons).

Answer:

C. \(1s^22s^1\)