What is the electron configuration for Argon?

The electron configuration of Argon, a noble gas with an atomic number of 18, reflects its complete filling of the electron shells. To arrive at the correct configuration, it's important to understand how electrons fill the orbitals according to the Aufbau principle, which states that electrons occupy the lowest energy orbitals first.

Argon has 18 electrons, and its electron configuration can be built starting from the first energy level. Initially, you fill the 1s orbital with 2 electrons: 1s². Next, you fill the 2s and 2p orbitals: 2s² 2p⁶, accumulating 10 electrons. Then, you move to the third shell, filling the 3s and 3p orbitals: 3s² 3p⁶, bringing the total count to 18 electrons.

Therefore, the complete electron configuration for Argon is [Ne] 3s² 3p⁶, which indicates that the configuration includes the filled orbitals of Neon, along with the additional electrons in the 3s and 3p subshells.

This is why the option that provides the configuration [Ne] 3s² 3p⁶ correctly represents Arg