WAEC Chemistry 2023 Objective — Question 19
Question 19 of 50 from the West African Examinations Council (WAEC) Chemistry 2023 Objective paper, with the correct answer and a full explanation.
Advertisement
How many unpaired electrons are present in ₂₆Fe³⁺?
- A. 2
- B. 3
- C. 4
- D. 5Correct
Explanation
₂₆Fe = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶. The two 4s electrons and one 3d electron are removed to form Fe³⁺: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵. The five 3d electrons are all unpaired, so Fe³⁺ has five unpaired electrons.
Advertisement
Sign up free to unlock
- Score tracking
- Practice history
- Saved questions
- Progress dashboard
- Personalized sessions
- Weak-topic breakdown
…and/or go further with premium services and No Ads.