88
Ra
Radium
(226) | 2
8
18
32
18
8
2
|
88
Ra
Radium
(226) | 2
8
18
32
18
8
2
|
| General |
|---|
| Name | Radium | | Symbol | Ra | | Number | 88 | | Chemical series | Alkaline earth metals | | Group / Period | 2 / 7 | | Block | s-block | | CAS registry number | 7440-14-4 |
| Physical properties |
|---|
| State | solid | | Density | 5.5 g/cm3 | | Melting point | 973 K (700 °C, 1292 °F) | | Boiling point | 2010 K (1737 °C, 3159 °F) | | Critical point | |
| Atomic properties |
|---|
| Atomic Weight | (226) g/mol | | Crystal structure | cubic body centered | | Electronegativity | 0.9 | | Atomic radius | 215 pm | | Atomic radius (calculated) | | | Electron configuration | [Rn] 7s2 | | Electrons per shell | 2, 8, 18, 32, 18, 8, 2 | | Number of protons | 88 | | Number of neutrons | 138 |
|
Actinium