Ionisation Energies (OCR A-Level Chemistry A): Flashcards

Energy to remove 1e⁻ from each atom in 1 mol gas atoms to 1+ ions

$\text{X(g)} \rightarrow \text{X}^{+}\text{(g)} + \text{e}^{-}$

Atomic radius, nuclear charge, electron shielding

Less e⁻ repulsion & stronger nuclear attraction on remaining e⁻

Electron removed from inner shell closer to nucleus

Decreases

Radius & shielding increase outweigh nuclear charge increase

Generally increases

2p electron higher energy than 2s, easier to remove

Paired e⁻ in O repel, easier to remove despite higher charge