WAEC Chemistry 2023 Objective — Question 21
Question 21 of 50 from the West African Examinations Council (WAEC) Chemistry 2023 Objective paper, with the correct answer and a full explanation.
Advertisement
Which of the following elements has its valence electrons in the s-orbital?
- A. SodiumCorrect
- B. Carbon
- C. Phosphorus
- D. Aluminium
Explanation
₁₁Na = 1s² 2s² 2p⁶ 3s¹; ₆C = 1s² 2s² 2p²; ₁₅P = 1s² 2s² 2p⁶ 3s² 3p³; ₁₃Al = 1s² 2s² 2p⁶ 3s² 3p¹. Sodium has its valence electron in the s-orbital, while the others have valence electrons in both s and p orbitals.
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.