Answer:
To denote a stable inner configuration and it represents argon
Explanation:
The symbol [Ar] used in the electron configuration of potassium represents the inner electronic configuration of the element.
This argon atom is stable octet with completely filled shells. Most noble gases are used to write the electronic configuration of other atoms. The inner atomic orbitals of elements are similar to those of nearby noble gases.
- Ar is Argon with a configuration of 1s² 2s² 2p⁶ 3s² 3p⁶
- So, this configuration is stable and it the inner configuration of potassium excluding the outermost orbitals.
