65 - Terbium lanthanide
Discovered by Carl Gustaf Mosander in 1843
Terbium is a chemical element with symbol Tb and atomic number 65. It is a silvery-white rare earth metal that is malleable, ductile and soft enough to be cut with a knife. Terbium is never found in nature as a free element, but it is contained in many minerals, including cerite, gadolinite, monazite, xenotime and euxenite.
Periodic table
| Shell | Electrons | Orbitals |
|---|---|---|
| 1 | 2 | 2 in 1s |
| 2 | 8 | 2 in 2s + 6 in 2p |
| 3 | 18 | 2 in 3s + 6 in 3p + 10 in 3d |
| 4 | 27 | 2 in 4s + 6 in 4p + 10 in 4d + 9 in 4f |
| 5 | 8 | 2 in 5s + 6 in 5p |
| 6 | 2 | 2 in 6s |
Electron shells
silvery white Appearance
159 u Atomic Mass
1.75 Å Atomic Radius
3.5k K Boiling Point
11 Group
3 Common Oxidation States
1.94 Å Covalent Radius
8.23 g/cm³ Density
112 kJ/mol Electron Affinity
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f9 Electron Configuration
[Xe] 4f9 6s2 Electron Configuration (semantic)
1.2 Electronegativity
65 Electrons
5.86 eV First Ionization Energy
3, 4 ICSD Oxidation States
565.8, 1110, 2114, 3839 kJ/mol Ionization Energies
1.63k K Melting Point
26 Mendeleev Number
28.9 J/(mol·K) Molar Heat
6 Number of Shells
94 Neutrons
65 Atomic Number
24 Number of Isotopes
1, 3, 4 Oxidation States
6 Period
Solid Phase
65 Protons
2, 8, 18, 27, 8, 2 Electron Shell Occupations