Respuesta :
They have the same number of electron shells.
PERIOD 1: K shell
PERIOD 2: K, L shell
PERIOD 3: K, L, M shell
etc.
PERIOD 1: K shell
PERIOD 2: K, L shell
PERIOD 3: K, L, M shell
etc.
They have the same number of electrons in their orbital. Meaning that they all share the same properties.
Final answer: Electrons Shells
Final answer: Electrons Shells