Thallium

Symbol | Tl
Latin name | Thallium
Atomic number | 81
Period | 6
Element category | Metals
Relative atomic mass | 204.3833
Group | III.A
Electronegativity | 1.8
Oxidation numbers | 1, 3
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p1
Density [g/cm3] | 11.85
State | Solid
Melting point [°C] | 303.5
Boiling point [°C] | 1457
Thermal conductivity [W m-1K-1] | 46.1
Heat capacity [J K-1g-1] | 0.129
Discovery | 1861
Hardness [Mohs scale] | 1.2
Young's modulus [GPa] | 8
Electrical conductivity [S m-1] | 5.6 · 106
Shear modulus [GPa] | 2.8
1.st ionization energy [eV] | 6.1083
2.nd ionization energy [eV] | 20.428
3.rd ionization energy [eV] | 29.829
Stable isotopes | 2
Unstable isotopes | 26