21 - Scandium transition metal
Discovered by Lars Fredrik Nilson in 1878
Scandium is a chemical element with symbol Sc and atomic number 21. A silvery-white metallic d-block element, it has historically been sometimes classified as a rare earth element, together with yttrium and the lanthanoids. It was discovered in 1879 by spectral analysis of the minerals euxenite and gadolinite from Scandinavia.
H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
57-71 La-Lu Lanthanides
89-103 Ac-Lr Actinides
| Shell | Electrons | Orbitals |
|---|---|---|
| 1 | 2 | 2 in 1s |
| 2 | 8 | 2 in 2s + 6 in 2p |
| 3 | 9 | 2 in 3s + 6 in 3p + 1 in 3d |
| 4 | 2 | 2 in 4s |
45 u Atomic Mass
2.1 Å Atomic Radius
3.11k K Boiling Point
1.7 Å Covalent Radius
2.98 g/cm³ Density
18 Electron Affinity
1.36 Electronegativity
6.56 eV First Ionization Energy
1.81k K Melting Point
4 Number of Shells
21 Atomic Number
2, 8, 9, 2 Electron Shell Occupations