The arrangement of sub shells or orbitals is according to _ rule?

Explanation

The arrangement of subshells or orbitals within an atom is based on the principle known as the Aufbau principle. According to the Aufbau principle, electrons fill the available orbitals in order of increasing energy, starting from the lowest energy level. The notation used to represent the arrangement of subshells or orbitals is based on the quantum numbers. The principal quantum number (n) determines the energy level or shell, and the azimuthal quantum number (l) determines the subshell or orbital shape. The subshells or orbitals are filled in the order of increasing values of (n+1). For example, the filling order of subshells is as follows: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, etc. Each subshell or orbital can hold a specific number of electrons based on their shape and orientation. The Aufbau principle helps determine the electron configuration of an atom and provides insights into the arrangement of electrons within an atom's energy levels and subshells.