JEE MAIN - Chemistry (2024 - 9th April Evening Shift - No. 4)
The electronic configuration of Einsteinium is :
(Given atomic number of Einsteinium $$=99$$)
$$[\mathrm{Rn}] 5 \mathrm{f}^{13} 6 \mathrm{~d}^{\circ} 7 \mathrm{~s}^2$$
$$[\mathrm{Rn}] 5 \mathrm{f}^{12} 6 \mathrm{~d}^{\circ} 7 \mathrm{~s}^2$$
$$[\mathrm{Rn}] 5 \mathrm{f}^{11} 6 \mathrm{~d}^{\circ} 7 \mathrm{~s}^2$$
$$[\mathrm{Rn}] 5 \mathrm{f}^{10} 6 \mathrm{~d}^{\circ} 7 \mathrm{~s}^2$$
Explanation
The correct option for the electronic configuration of Einsteinium (atomic number 99) is:
Option C: [Rn] 5f11 6d0 7s2Here's why:
- Atomic Number and Electrons: Einsteinium has an atomic number of 99, which means it has 99 protons in its nucleus. Since atoms are neutral, it also has 99 electrons surrounding the nucleus.
- Electron Shells: Electrons fill up energy shells around the nucleus. The order of filling follows the Aufbau principle, which generally fills lower energy shells before moving to higher ones.
- Noble Gas Core Notation: The notation [Rn] represents the filled electron configuration of Radon (atomic number 86). This is a shorthand to avoid writing out the entire configuration of the inner shells, as they are not involved in the chemical behavior of Einsteinium.
- Filling the f-orbital: Einsteinium is an actinide element, located in the f-block of the periodic table. The 5f subshell fills up after the 6s subshell.
- Aufbau Principle: According to the Aufbau principle, the 5f subshell can hold up to 14 electrons. In Einsteinium, 11 electrons fill the 5f subshell (5f11).
- Empty d-orbital: The 6d subshell has a higher energy level than the 5f subshell. Since the 5f subshell isn't completely filled, the 6d subshell remains empty (6d0).
- Outermost Electrons: The remaining two electrons fill the outermost 7s subshell (7s2).
Therefore, the complete electronic configuration of Einsteinium is:
[Rn] 5f11 6d0 7s2Comments (0)
