Question
What is the atomic number of first post actinoid element ?
MHT CET
Chemistry
d and f Block Elements
2026
MHT CET 2026 (17 April Shift 2)
MHT CET Chemistry Question (2026) — Solution
Options
- A. 101
- B. 108
- C. 104
- D. 110
Answer
C. 104
Step-by-step solution
The actinoid series consists of elements with atomic numbers from 90 to 103. The elements that follow the actinoid series are known as post-actinoid elements. Therefore, the first post-actinoid element has an atomic number of 104, which is Rutherfordium (Rf). Answer: 104
Related: Chemistry — d and f Block Elements · All PYQ Banks