Stable isotope Radium (Ra)

Isotope Atomic Mass Half-life Mode of Decay Nuclear Spin Nuclear Magnetic Moment
Ra-223 223.018497 11.435 days α to Rn-219; C-14 3/2 0.271
Ra-224 224.020202 3.66 days α to Rn-220; C-12 0 No data available
Ra-225 225.023603 14.90 days β- to Ac-225 3/2 -0.734
Ra-226 226.025403 1599 years α to Rn-222; C-14 0 No data available
Ra-227 227.029170 42 minutes β- to Ac-227 3/2 -0.404
Ra-228 228.031063 5.76 years β- to Ac-228 0 No data available

Properties of Radium

Name Radium
Symbol Ra
Atomic number 88
Atomic weight 226
Standard state Solid at 298 °K
CAS Registry ID 7440-14-4
Group in periodic table 2
Group name Alkaline earth metal
Period in periodic table 7
Block in periodic table s-block
Color Metallic
Classification Metallic
Melting point 700 °C
Boiling point 1737 °C
Thermal conductivity 19 W/(m·K)
Electrical resistivity 100 x 10-8 Ω·m
Electronegativity 0.9
Heat of vaporization About 125 kJ·mol-1
Heat of fusion About 8 kJ·mol-1
Density of solid 5.00 g/cm3
Electron configuration [Rn]7s2
Oxidation state +2