What element has the electron configuration 1s2 2s2 2p6 3s2 3p4 4s2 3d5 and how do you know?
The Correct Answer and Explanation is :
The element with the electron configuration 1s² 2s² 2p⁶ 3s² 3p⁴ 4s² 3d⁵ is manganese (Mn).
To determine which element has this electron configuration, we can count the total number of electrons represented by it. The sum of the electrons in each orbital gives us the atomic number of the element:
- 1s²: 2 electrons
- 2s²: 2 electrons
- 2p⁶: 6 electrons
- 3s²: 2 electrons
- 3p⁴: 4 electrons
- 4s²: 2 electrons
- 3d⁵: 5 electrons
Adding these up, (2 + 2 + 6 + 2 + 4 + 2 + 5 = 25). The atomic number 25 corresponds to manganese on the periodic table.
Manganese’s electron configuration is particularly notable because it includes electrons in the 3d orbital. Transition metals like manganese often have electrons in their d orbitals. This configuration, with five electrons in the 3d orbital and two in the 4s, is a typical arrangement for transition metals in the middle of the first series. The presence of five d electrons is a stable and energetically favorable configuration due to the half-filled d orbital, which provides added stability.
The sequence of filling orbitals starts with the lower energy levels first (1s, 2s, 2p, etc.). However, in transition metals, the 4s orbital is filled before the 3d orbitals start filling. Interestingly, in many transition elements, electrons from the 4s orbital are used in bonding before the 3d, which can be seen in various chemical reactions and compounds involving manganese.
Now, let’s generate an image representing manganese’s electron configuration.
Here is the illustration depicting the electron configuration of manganese (Mn), showing the arrangement of electrons in various orbitals. This educational image visually represents the sequence and distribution of electrons across the different energy levels, labeled for clarity.
