What is the electronic configuration of argon?

Argon is a noble gas with the atomic number 18, meaning it has 18 electrons. The electronic configuration of an atom describes how these electrons are distributed in its atomic orbitals.

In the case of argon, the electrons fill the orbitals in the following order:

• The first energy level (closest to the nucleus) can hold a maximum of 2 electrons. Thus, the first energy level is filled with 2 electrons.
• The second energy level can hold up to 8 electrons. In argon, this level is also fully occupied, containing 8 electrons.
• The third energy level, similar to the second, can hold up to 8 electrons, but in argon, it is not filled beyond 8 since argon itself only has 18 electrons total.

Therefore, the electronic configuration of argon is typically expressed as 2 electrons in the first level, 8 in the second, and 8 in the third. This is represented as 2.8.8.

This configuration indicates that argon has a stable electronic arrangement, which is one reason why it is chemically inert and does not readily form compounds.