what is penultimate shell
The outermost shell (shell-3) of an atom is called valence shell while second last shell (shell-2) is called penultimate shell and the 3rd last (shell-1) is called Ante-penultimate shell
what is penultimate shell
The outermost shell (shell-3) of an atom is called valence shell while second last shell (shell-2) is called penultimate shell and the 3rd last (shell-1) is called Ante-penultimate shell