1.3C Electron Configurations of Atoms and Ions

Why do we use Noble Gases as shorthands? What are the electron configurations for Helium, Neon and Argon?

Noble Gases have complete shells and it makes it more convenient

He (2e-) = 1s²

Ne (10e-) = 1s² 2s² 2p^6

Ar (18e) = 1s² 2s² 2p^6 3s² 3p^6

What is important about the 4s sub level?

Electrons are lost from the 4s sublevel first

What do Electron Configs look like with Negative Ions?

What do Electron Configs look like with Positive Ions?

What do Electron Configs look like with Transition Metals?

• Transition metal ions don’t always follow the pattern of taking on the electron configuration of the closest noble gas

• Transition metal electron configurations must be determined from the charge on the ion