Rubidium
Main page |
| Other names/abbreviations: | Rb |
| Element no: | 37 |
| Element group: | 1 (IUPAC) I A (American labelling) I A (European labelling) Alkali metals |
| Element type: | Metals |
| CAS-Number: | 7440-17-7 |
| EINECS-Number: | 231-126-6 |
Safety
Symbol: F, CR-phrases: 14/15-34
S-phrases: 8-26-36/37/39-43-45
Physical properties
Appearance | ||
| Physical state @ 20°C: | Solid [3] | |
| Color: | Metallic sheen [3] | |
| Odor: | Odourless [3] | |
Bulk properties | ||
| Molecular weight (g/mol): | 85.4678(3) [1] | |
| Melting point (°C): | 39.5 [1] | |
| Boiling point (°C): | 688 [1] | |
| Density (g/cm3): | 1.532 [1] | |
| Molar volume (cm3): | 55.87 (20 °C) [2] | |
| Elastic properties: Young's modulus (GPa): Rigidity modulus (GPa): |
2.35 [2] 0.91 [2] | |
| Hardnesses: Mineral hardness: |
0.3 [2] | |
Thermodynamic properties | ||
| ΔfH°gas (kJ/mol): | 82.0 (monoatomic) [1] 80.9 [4] | |
| ΔfH°solid (kJ/mol): | 0.0 [4] | |
| ΔH°fusion (kJ/mol): | 2.20 [1] | |
| ΔH°vaporization (kJ/mol): | 76 [1] | |
| S°gas (J/K·mol): | 170.1 [4] | |
| S°solid (J/K·mol): | 76.8 [4] | |
| ΔfG°gas (kJ/mol): | 53.1 [4] | |
| Cp (gas) (J/K·mol): | 20.8 (25 °C) [4] | |
| Cp (solid) (J/K·mol): | 31.060 (25 °C) [4] | |
Crystal structure | ||
| Crystal type: | Body centered cubic [2] | |
Electronic properties | ||
 |
Electron configuration: | 1s2-2s2-2p6-3s2-3p6-3d10-4s2-4p6-5s1 |
| Atomic radius (Å): | 2.44 [5] | |
| Ionic radius (Å): | 1.52 [1] | |
| Electron affinity [M-M-] (kJ/mol): | 46.88 [1] | |
Conductivity | ||
| e°(V): | Rb(I)/Rb: -2.925 [1] | |
| Electrical resisitvity (μΩ·cm): | 612.10 (20 °C) [2] 13.30 (25 °C) [2]] | |
| Thermal (W/m·K): | 58.2 (27 °C) [4] | |
References
1: Greenwood,N.N., Earnshaw,A. Chemistry of the elements2nd edition (1997) Edited by Greenwood,N.N., Earnshaw,A. pp. 1-1340, Butterworth-Heinemann. Oxford. Great Britain
2: Buch,A. Pure Metals Properties. A Scientific-Technical Handbook
1st edition (1999) Edited by Buch,A. pp. 1-306, ASM International and Freund Publishing House Ltd. Ohio. USA
3: Merck. ChemDAT The Merck Chemical Database Ver. 1.1.5
4: CRC Handbook of Chemistry and Physics
75th edition (1994) Edited by Lide,D.R. , CRC Press Inc. Boca Raton, USA
5: General chemistry
7th edition (1984) Edited by Holtzclaw, Jr.,H.F., Robinson,W.R. & Nebergall,W.H. pp. 1-932. D.C. Heath and Company. Lexington
© Michael Pilgaard
Created: October 6, 2008
Last update: October 9, 2008