What is the electron configuration for Beryllium?

The electron configuration for Beryllium is correctly represented as [He] 2s^2. Beryllium, which has an atomic number of 4, contains a total of four electrons. The first two electrons fill the 1s orbital, which corresponds to the highest energy level of the noble gas helium, represented as [He]. The remaining two electrons go into the next available energy level, which is the 2s orbital.

This configuration indicates that Beryllium has its electrons organized in such a way that the 2s subshell is fully filled with two electrons, while there are no electrons in the 2p subshell at this stage. The choice reflects the correct filling order according to the Aufbau principle, where electrons fill the lowest energy orbitals first before moving to higher energy levels. Therefore, the correct configuration highlights that only the 2s subshell is filled, which is accurate for Beryllium's distribution of electrons.