Question
Which of the following elements has completely filled 4 f orbital at the expected ground state configuration?
MHT CET
Chemistry
d and f Block Elements
2026
MHT CET 2026 (15 April Shift 2)
MHT CET Chemistry Question (2026) — Solution
Options
- A. La
- B. Yb
- C. Eu
- D. Gd
Answer
B. Yb
Step-by-step solution
The electronic configurations of the given elements in their ground state are: La (Z=57) : [ Xe ] 5d^ 1 6s^ 2 Yb (Z=70) : [ Xe ] 4f^ 14 6s^ 2 Eu (Z=63) : [ Xe ] 4f^ 7 6s^ 2 Gd (Z=64) : [ Xe ] 4f^ 7 5d^ 1 6s^ 2 Thus, Ytterbium ( Yb ) has a completely filled 4f orbital. Answer: Yb
Related: Chemistry — d and f Block Elements · All PYQ Banks