Choosing the Ground State Electron Configuration for Ti²⁺
Titanium (Ti) is a transition metal with atomic number 22. Understanding its electron configuration, and specifically that of its 2+ ion (Ti²⁺), requires knowledge of electron filling rules and the principles governing transition metal ion formation.
The neutral titanium atom has an electron configuration of [Ar] 3d² 4s². This means it has 2 electrons in the 4s subshell and 2 electrons in the 3d subshell, in addition to the 18 electrons of Argon's stable configuration.
How Ti²⁺ is formed: When titanium loses electrons to form a cation, it loses them from its highest energy level first. This means it loses the 4s electrons before the 3d electrons.
Therefore, the ground state electron configuration for Ti²⁺ is [Ar] 3d². It has lost its two 4s electrons, leaving the two 3d electrons remaining.
Frequently Asked Questions (Addressing Potential "People Also Ask" Queries)
What are the rules for determining electron configurations?
Electron configuration follows the Aufbau principle, Hund's rule, and the Pauli exclusion principle. The Aufbau principle dictates that electrons fill orbitals from lowest to highest energy levels. Hund's rule states that electrons fill orbitals individually before pairing up within a subshell. The Pauli exclusion principle states that no two electrons in an atom can have the same four quantum numbers. For transition metals, filling order can become less straightforward due to energy level differences, but the general principle of removing the highest energy electrons first during ion formation remains key.
What is the difference between the electron configuration of Ti and Ti²⁺?
The neutral titanium atom (Ti) has the electron configuration [Ar] 3d² 4s², while the titanium(II) ion (Ti²⁺) has the configuration [Ar] 3d². The key difference is the loss of the two 4s electrons during the formation of the 2+ cation.
Why does Ti lose its 4s electrons before its 3d electrons?
While the 3d and 4s orbitals are close in energy, the 4s electrons are generally considered to be at a slightly higher energy level than the 3d electrons in transition metals. Therefore, they are more easily removed during ionization.
How do I write electron configurations for other transition metal ions?
The process is similar for other transition metal ions. Identify the neutral atom's electron configuration, then remove electrons from the highest energy level(s) to reach the desired charge. For transition metals, it's usually the outer s electrons that are lost first. However, it's always advisable to consult reliable resources such as periodic tables with electron configurations to verify your work.
Are there exceptions to the electron configuration rules for transition metals?
While the rules provide a good guideline, there can be some exceptions, particularly in highly charged ions or complex situations due to ligand field effects (relevant in coordination chemistry). These exceptions arise from complex interactions between electrons and the surrounding environment. For simple ions like Ti²⁺, the standard rules accurately predict the electron configuration.
