Write the formula for scandium sulfate.
Sc3+ and SO4 2- cross to a common multiple of 6: Sc2(SO4)3 — structurally identical to aluminum sulfate.
What Is the Charge of Scandium?
Scandium commonly forms Sc3+ in introductory ionic compounds.
Scandium is effectively a one-charge metal: Sc3+, as in Sc2O3 and ScF3. Although it opens the transition-metal block, it behaves more like aluminum — one charge, no Roman-numeral guessing games.
| Element | Scandium |
|---|---|
| Symbol | Sc |
| Atomic number | 21 |
| Common ionic charge | +3 |
| Common ions | Sc3+ |
Visual reference
Scandium element image and atomic model
Images are used as visual references; charge rules still depend on the compound.
Where Scandium's charge options come from
Scandium is [Ar]3d1 4s2. Losing all three outer electrons (two 4s, one 3d) leaves the bare argon core, and there is no stable partial stop along the way. With no d electrons left to shuffle, Sc3+ has no alternative oxidation states worth learning.
This is a classroom reference range, not an exhaustive list of all oxidation states.
The trap in Scandium problems
Expecting scandium to have variable charges 'because it's a transition metal.' Position in the d-block doesn't automatically mean multiple charges — scandium, along with zinc and silver, is one of the block's fixed-charge exceptions.
Worked example: Sc in a formula problem
Sc3+ in real compounds
ScCl3
Scandium chloride
Sc3+ balances chloride ions.
Sc2O3
Scandium oxide
Scandium can form oxides where total positive and negative charge balances.
Questions students ask about scandium
Why is Sc3+ colorless when most transition-metal ions are colorful?
Color in transition-metal ions comes from electrons jumping between d orbitals. Sc3+ has zero d electrons left — no d-d jumps, no color. The same logic explains colorless Zn2+ (full d shell).
Where would I actually meet scandium?
Scandium-aluminum alloys in bike frames and aerospace parts, and ScI3 in stadium lights. In the alloy it is neutral metal; in the iodide it is Sc3+.
Does scandium count as a rare earth?
Yes — IUPAC groups scandium and yttrium with the lanthanides as 'rare earth elements' because all favor the same 3+ charge and hunt together in the same ores.
How do I use this charge in formulas?
Combine positive and negative ions so the total charge is zero — or let the ionic compound calculator do the crossing for you. The full chart lives on the periodic table with charges.
Where this data comes from
Charges and element facts on this page are checked against the primary references below. Found an error? Email hello@periodictablewithcharges.com — corrections ship in the next content update. See how this site is edited.