Scandium (Sc)
Scandium is element 21, a transition metal in period 4, group 3 of the periodic table. At room temperature it is a solid.
Electron configuration [Ar] 3d1 4s2
Electrons per shell 2, 8, 9, 2
Scandium data
| Atomic number | 21 |
|---|---|
| Symbol | Sc |
| Atomic mass | 44.956 u |
| Category | Transition metal |
| Group | 3 |
| Period | 4 |
| Block | d |
| State at 25 °C | solid |
| Melting point | 1814 K (1540.9 °C) |
| Boiling point | 3103 K (2829.9 °C) |
| Density | 2.985 g/cm³ |
| Electronegativity (Pauling) | 1.36 |
| Atomic radius | 144 pm |
| 1st ionization energy | 633 kJ/mol |
| Electron affinity | -18 kJ/mol |
| Oxidation states | +1, +2, +3 |
| Common ion charge | 3+ |
| Discovered | 1876 |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through scandium’s configuration and its ions →
Where scandium sits
Scandium belongs to the transition metals. Its Pauling electronegativity of 1.36 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.
Scandium FAQ
What is the electron configuration of scandium?
Scandium (Z = 21) has the configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2. In noble-gas shorthand that is [Ar] 3d1 4s2.
How many valence electrons does scandium have?
3 (2 outer s + 1 d electrons; 2 in the outermost shell).
What is the atomic mass of scandium?
The standard atomic weight of scandium is 44.956 u, so one mole weighs 44.956 g.
Is scandium a metal?
Yes. Scandium is a transition metal.
What is the charge of a scandium ion?
Scandium most commonly forms Sc3+.