Atomic Number (# of protons)

57

Mass (amu)

138.9

Density

6.15 g/cm³ (20⁰C, 1 atm)

Electron Configuration

[Xe]5d¹6s²

Oxidation States (bold = most stable)

+3

Atomic Radius (pm)

187

Ionic Radius (pm)

(+3)116

Electronegativity

1.1

Melting Point (⁰C, 1 atm)

918

Electron Affinity (eV)

0.5

Boiling Point(⁰C, 1 atm)

3464

1^st Ionization energy (eV)

5.77

Enthalpy of Fusion (kJ/mole)

6.20

2^nd Ionization Energy (eV)

Enthalpy of Vaporization (kJ/mole)

399.6

3^rd Ionization Energy (eV)

Specific Heat Capacity ( J/ (g K), 25⁰C, 1 atm)

0.20