Scandium (symbol Sc) is a chemical element with the atomic number 21. It is the very first element in the 'd-block' (transition metals) of the periodic table, making its electron configuration an important learning step in Chemistry.
Because Scandium usually only forms the Sc³⁺ ion (where its d-orbital becomes completely empty), some chemists debate whether it should truly be classified as a typical 'transition metal', since typical transition metals have partially filled d-orbitals in their ions.
Since Scandium has 21 electrons, they are distributed into the energy levels as follows:
Full Configuration (spdf notation): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹
Shorthand (Noble Gas) Configuration: [Ar] 4s² 3d¹ (This shorthand is used because the first 18 electrons perfectly match the electron configuration of the noble gas Argon [Ar]).
According to the Aufbau Principle (and the n+l rule), electrons fill the lowest energy orbitals first. The 4s orbital has slightly lower energy than the 3d orbital. Therefore, the 4s orbital fills up first with 2 electrons (reaching element 20, Calcium), and the 21st electron of Scandium enters the 3d orbital.
When Scandium forms bonds, it usually loses 3 electrons to become the Sc³⁺ ion. It loses the two 4s electrons and the one 3d electron, leaving it with the stable electron configuration of Argon: [Ar].
The most common and stable valency (oxidation state) of Scandium is **+3**.
What is a Ligand?
Learn the definition of a ligand in chemistry. Understand how molecules or ions donate electron pairs to a central metal atom in coordination compounds.
What is a Polyatomic Ion? (Definition & Examples)
Learn the definition of a polyatomic ion in chemistry. Discover clear examples like Sulphate (SO4), Nitrate (NO3), and Ammonium (NH4) for Class 9 students.
What is the Degree of Dissociation?
Learn the definition and formula for the degree of dissociation (alpha). Understand its importance in weak acids, weak bases, and chemical equilibrium.
Density of Petrol — What Is the Density of Petrol (Gasoline)?
The density of petrol (gasoline) is approximately 0.71–0.77 g/mL (710–770 kg/m³). It is less dense than water, which is why petrol floats on water. Learn with FAQs.
What Is Desiccated Coconut? Drying Process and Chemistry Explained
Desiccated coconut is coconut flesh with moisture removed by drying at low temperatures. It preserves coconut by reducing water activity, inhibiting microbial growth. Used widely in food.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.