Question

What is the electron configuration of He, Ne, Ar, Kr, Xe, Rn

Answer 1

He : electronic configuration of He is 1s²

Ne : electronic configuration of Ne is 1s² 2s² 2p⁶. It is customary to represent a configuration using the last noble gas passed. i.e., it can be represented as [He] 2s² 2p⁶. Here [He] implies its configuration i.e.,1s².

Ar : The noble gas before Ar is Ne. Thus configuration is [Ne] 3s² 3p⁶

Kr : The noble gas before Kr is Ar. Thus configuration is [Ar] 3d¹⁰ 4s² 4p⁶

Xe : The noble gas before Xe is Kr. Thus configuration is [Ar] 4d¹⁰ 5s² 5p⁶

Rn : The noble gas before Rn is Xe. Thus configuration is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶