Ceist Eile is in development. Features, questions and prices may change while we refine it.

Leaving Cert Chemistry: Electron configuration

How often Electron configuration comes up on the Chemistry papers, every year it was asked, and questions to try.

HL Asked on 9 of the last 10 Higher Level papers, most recently in 2025. banker

OL Asked on 2 of the last 10 Ordinary Level papers, most recently in 2018.

June 2027 is the first exam on the new Chemistry course. These come from the 2016–2026 papers, so read them as a guide.

Electron configuration, Higher Level(7 marks)

Quick ones on Electron configuration.

(a)Maximum number of electrons in a d sublevel?

(b)Electron configuration of the chloride ion, Cl- (chlorine is Z = 17)?

(c)Principle stating that electrons fill the lowest available energy sublevels first?

Show the answers

(a) 10

(b) 1s2 2s2 2p6 3s2 3p6

(c) Aufbau principle

Your turn: Higher Level questions on Electron configuration.

Higher Level

Asked on 9 of the last 10 Higher Level papers, most recently in 2025. banker

Links open the State Examinations Commission’s paper for that year.

Asked on 2 of the last 10 Ordinary Level papers, most recently in 2018.

Links open the State Examinations Commission’s paper for that year.