Answer:
According to Hund's rule and the Aufbau principle in which the orbitals must be filled with electrons, they are not strictly applied in the real universe, because the intermediate and electron-filled atomic orbitals are very stable . Because there are four d-orbitals in universe L, a typical half-full configuration will be xd4 and its full configuration will be xd8, where x is the primary orbital for any specific element. Here is an example:
Vahadium ₂₃V
in real universe: [Ar]₈ 3d³4s²
in universe L: [Ar]₁₈ 3d⁴4s¹
Chromium
in real universe: [Ar]₈ 3d⁵4s¹
in universe L: [Ar]₁₈ 3d⁴4s²
Step-by-step explanation: