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 |