How many electrons are present in the d sublevel of a Mn4+ ion?
The Correct Answer and Explanation is:
The manganese ion Mn4+\text{Mn}^{4+}Mn4+ has 4 electrons removed from its neutral atomic state. To determine the number of electrons in the ddd-sublevel of this ion, let’s first examine the electron configuration of neutral manganese and then how the removal of electrons affects the ddd-sublevel.
Step 1: Electron configuration of neutral manganese (Mn)
Manganese has an atomic number of 25, meaning that a neutral manganese atom has 25 electrons. The electron configuration of Mn is:Mn:[Ar] 4s2 3d5\text{Mn}: [Ar] \, 4s^2 \, 3d^5Mn:[Ar]4s23d5
This configuration means that in the neutral state, manganese has:
- 2 electrons in the 4s orbital
- 5 electrons in the 3d orbital
Step 2: Removing electrons to form Mn4+\text{Mn}^{4+}Mn4+
When manganese forms a Mn4+\text{Mn}^{4+}Mn4+ ion, it loses 4 electrons. These electrons are generally removed first from the 4s4s4s-sublevel, followed by the 3d3d3d-sublevel. Therefore, the removal of 4 electrons from Mn results in the following electron configuration:Mn4+:[Ar] 3d5\text{Mn}^{4+}: [Ar] \, 3d^5Mn4+:[Ar]3d5
In this configuration, the 4 electrons are removed from the 4s24s^24s2 and partially from the 3d53d^53d5 orbitals. However, since the 3d3d3d-sublevel is more stable than the 4s4s4s-sublevel, all 4 electrons are removed from the 4s4s4s-sublevel, leaving the 3d3d3d-sublevel intact.
Step 3: Number of electrons in the ddd-sublevel
After the loss of 4 electrons, the Mn4+\text{Mn}^{4+}Mn4+ ion has 5 electrons in its 3d3d3d-sublevel.
Conclusion
The number of electrons in the ddd-sublevel of a Mn4+\text{Mn}^{4+}Mn4+ ion is 5 electrons.
