WAEC Chemistry 2013 Objective — Question 7
Question 7 of 50 from the West African Examinations Council (WAEC) Chemistry 2013 Objective paper, with the correct answer and a full explanation.
Advertisement
The element with electron configuration 1s²2s²2p⁶ 3s²3p¹ belongs to
- A. s-block, period 3, group 1
- B. p-block, period 3, group 2
- C. s-block, period 3, group 3
- D. p-block, period 3, group 3Correct
Explanation
The s.p.d.f notation is employed to tell the block an element belongs. If the electronic configuration ends in s, the element belongs to S-block; if it ends in p, the element belongs to P-block etc. Since the given electronic configuration is 1s²2s²2p⁶3s²3p¹, the element belongs to P-block. We can also tell the group and period from the s.p.d.f notation: the maximum principal quantum number is the period number while the total number of electrons in the outermost orbitals is the group number. Thus, group=3, period=3.
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.