Is Aluminum a Transition Metal? (+ 3 More Things to Know)

No, aluminum is not considered a transition metal. Transition metals are elements that are found in the d-block of the periodic table, specifically in the middle section between Group 2 (alkaline earth metals) and Group 11. While aluminum is a metallic element, it is not classified as a transition metal. ¹

Well, this was just a simple answer. But there are few more things to know about this topic which will make your concept super clear.

So let’s dive right into it.

Why is aluminum not a transition metal?

Aluminum is not classified as a transition metal due to its electronic configuration and the absence of partially filled d-orbitals in its valence shell. Transition metals are defined by having partially filled d-orbitals in at least one of their common oxidation states. ²

In the case of aluminum, it belongs to Group 13 of the periodic table, also known as the boron group. It has an atomic number of 13 and an electronic configuration of [Ne] 3s² 3p¹. ³ This configuration means that aluminum has completely filled 2s and 2p orbitals, and its valence electrons are in the 3s and 3p orbitals. ⁴

Transition metals, on the other hand, have valence electrons in both the s and d orbitals. These metals often exhibit multiple oxidation states because they can lose different numbers of electrons from both the s and d orbitals, resulting in the formation of various stable ions.

While aluminum does exhibit some metallic properties, such as good conductivity and malleability, it lacks the characteristic electronic configuration and partially filled d-orbitals that define the transition metal group. Therefore, it is not classified as a transition metal, but rather as a representative element or a main-group element in Group 13 of the periodic table. ⁵

What are the characteristics of transition metals? And how aluminum differs from transition metals?

Here are a few characteristics of transition metals and showing how aluminum is different from these transition metals.

• Partially filled d-orbitals: Transition metals have electrons occupying the d-orbitals in their electron configuration. Aluminum, however, does not have any electrons in its d-orbitals. Its electron configuration of [Ne] 3s² 3p¹ indicates that the d-orbitals are not involved in its valence shell. ⁶
• Variable oxidation states: Transition metals can exist in multiple oxidation states due to the availability of partially filled d-orbitals, which can readily accept or donate electrons. In contrast, aluminum typically exhibits only one oxidation state, which is +3. ⁷ It does not have the flexibility to exhibit different oxidation states like transition metals do.
• Formation of colored compounds: Transition metals are known for forming colored compounds due to the presence of partially filled d-orbitals, which absorb specific wavelengths of light. ⁸ Aluminum compounds, however, do not typically exhibit vibrant colors associated with transition metal compounds because it lacks the partially filled d-orbitals responsible for the absorption and transmission of light.

Therefore, due to its electronic configuration and the absence of partially filled d-orbitals, aluminum is not classified as a transition metal. It falls into the category of representative elements or main-group elements instead.

Further reading

Is Aluminum a Metal, Nonmetal or Metalloid?
Is Lead a Transition Metal?
Is Zinc a Transition Metal?
Is Copper a Transition Metal?
Is Oxygen a Halogen? 

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1. Boudreaux, K. A. (n.d.). The Parts of the Periodic Table. The Parts of the Periodic Table. https://www.angelo.edu/faculty/kboudrea/periodic/trans_transition.htm
2. IUPAC https://goldbook.iupac.org/terms/view/T06456
3. P. (n.d.). Periodic Table of Elements. Periodic Table of Elements – PubChem. https://pubchem.ncbi.nlm.nih.gov/periodic-table/
4. Electron Configuration for Aluminium (Al). (n.d.). Electron Configuration for Aluminium (Al). https://terpconnect.umd.edu/~wbreslyn/chemistry/electron-configurations/configurationAluminium.html
5. Aluminium – Element information, properties and uses | Periodic Table. (n.d.). Aluminium – Element Information, Properties and Uses | Periodic Table. https://www.rsc.org/periodic-table/element/13/aluminium
6. Periodic Table of Elements: Los Alamos National Laboratory. (n.d.). Periodic Table of Elements: Los Alamos National Laboratory. https://periodic.lanl.gov/13.shtml
7. Myers, T. W., Kazem, N., Stoll, S., Britt, R. D., Shanmugam, M., & Berben, L. A. (2011, May 13). A Redox Series of Aluminum Complexes: Characterization of Four Oxidation States Including a Ligand Biradical State Stabilized via Exchange Coupling. Journal of the American Chemical Society, 133(22), 8662–8672. https://doi.org/10.1021/ja2015718
8. 19.1: Properties of Transition Metals and Their Compounds. (2015, September 28). Chemistry LibreTexts. https://chem.libretexts.org/Bookshelves/General_Chemistry/Chemistry_1e_(OpenSTAX)/19%3A_Transition_Metals_and_Coordination_Chemistry/19.1%3A_Properties_of_Transition_Metals_and_Their_Compounds