The most energetic electron in any atom at the beginning of a period of the periodic table is in:
A)an ℓ=0 state
B)an ℓ=1 state
C)an ℓ=2 state
D)an n = 0 state with unspecified angular momentum
E)an n = 1 state with unspecified angular momentum

Question

Quizplus · Accepted Answer

At the beginning of a period in the periodic table, the most energetic electron in any atom is in the s orbital, which corresponds to an ℓ (azimuthal quantum number) of 0. This is because a new period starts with the filling of electrons in a new principal energy level (n) in the s orbital, indicating the lowest energy sublevel (ℓ=0) for that principal energy level.

The Most Energetic Electron in Any Atom at the Beginning