Be sure to answer all parts. Write the condensed ground-state electron configuration of the transition metal ion Mo3+. Is it paramagnetic? Condensed ground-state electron configuration: Paramagnetic? Yes No
The Correct Answer and Explanation is:
Condensed ground-state electron configuration of Mo³⁺: [Kr] 4d³ Paramagnetic? Yes
To determine the electron configuration of Mo³⁺, we begin with the ground-state configuration of a neutral molybdenum atom (atomic number 42). The condensed electron configuration of neutral Mo is:
[Kr] 5s¹ 4d⁵
Despite the expected filling order based on the Aufbau principle, Mo exhibits an anomalous configuration. This is due to increased stability gained by having a half-filled 4d subshell and a single electron in the 5s orbital.
When forming the Mo³⁺ ion, three electrons are removed. Ionization typically removes electrons from the outermost orbitals first. In this case, the 5s electron is lost first, followed by two electrons from the 4d subshell. Thus, the Mo³⁺ electron configuration becomes:
[Kr] 4d³
This ion has three unpaired electrons in the 4d subshell. Each unpaired electron contributes to magnetic behavior. The presence of these unpaired electrons confirms that the Mo³⁺ ion is paramagnetic. Paramagnetism arises when electrons are not all paired within an atom or ion, leading to a net magnetic moment that aligns with external magnetic fields. In contrast, a diamagnetic species would have all electrons paired and exhibit no such behavior.
The d-block elements, especially transition metals like molybdenum, often exhibit multiple oxidation states and unusual electronic configurations due to the close energy levels of their s and d orbitals. This variability allows for chemical versatility but also requires careful consideration of electron configurations when predicting properties like magnetism. Thus, the [Kr] 4d³ configuration and paramagnetism of Mo³⁺ are consistent with the known behavior of transition metal ions in moderate oxidation states.
