JEE MainChemistryClassification of Elements and Periodicity in Properties
The correct outer electronic configuration for the element with the IUPAC name Unnilseptium is
Options
- A[ Rn ] 5 f ¹⁴ 6 d ⁷ 7 s ²
- B[ Xe ] 4 f ¹⁴ 5 d ⁵ 6 s ²
- C[ Rn ] 5 f ¹⁴ 6 d ⁶ 7 s ¹
- D[ Rn ] 5 f ¹⁴ 6 d ⁵ 7 s ²
Correct answer
D. [ Rn ] 5 f ¹⁴ 6 d ⁵ 7 s ²
Step-by-step solution
The IUPAC name 'Unnilseptium' can be decoded using the numerical roots for elements with Z > 100 : un = 1 nil = 0 sept = 7 Thus, the atomic number of the element is Z = 107 . The nearest preceding noble gas is Radon (Rn), which has an atomic number of 86 . The number of electrons to be filled after Radon is 107 - 86 = 21 . According to the Aufbau principle, these 21 electrons are distributed into the 7 s , 5 f , and 6 d subshells. Filling order: 7 s takes 2 electrons, 5 f takes 14 electrons, and the remaining 5 ele