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57
La
138.9055
Lanthanum |
Appearance & Characteristics | Reactions |
Other Forms Radius | Conductivity | Abundance
General:
| Name: Lanthanum | Symbol: La |
| Group: Trans. Met. | Atomic weight: 138.9055 |
| Density @ 293 K: 6.7 g/cm3 | Atomic volume: 20.73 cm3/mol |
| Group: Trans. Met. | Discovered: 1839 |
States
| State (s, l, g): solid | |
| Melting point: 1193.2 K | Boiling point: 3693 K |
| Heat of fusion: 6.20 kJ/mol | Heat of vaporization: 414.0 kJ/mol |
Energies
| 1st ionization energy: 538.1 kJ/mole | |
| Electronegativity: 1.1 | 2nd ionization energy: 1067 kJ/mole |
| Electron affinity: 50 kJ/mole | 3rd ionization energy: 1850 kJ/mole |
| Specific heat: 0.19 J/gK | Heat atomization: 423 kJ/mole atoms |
Oxidation & Electrons
| Shells: 2,8,18,18,9,2 | Electron configuration: [Xe] 5d1 6s2 |
| Minimum oxidation number: 0 | Maximum oxidation number: 3 |
| Min. common oxidation no.: 0 | Max. common oxidation no.: 3 |
Appearance & Characteristics
| Structure: cp: close packed (ABCB) | Color: silvery-white |
| Uses: lighter flints, CRTs | Toxicity: |
| Hardness: mohs | Characteristics: soft, malleable |
Reactions
| Reaction with air: vigorous, w/ht => La2O3 | |
| Reaction with 6 M HCl: mild, => H2, LaCl3 | Reaction with 6 M HCl: mild, => H2, LaCl3 |
| Reaction with 15 M HNO3: mild, => La(NO3)3 | Reaction with 6 M NaOH: |
Other Forms
| Number of isotopes: 2 | Hydride(s): LaH2 LaH3 |
| Oxide(s): La2O3 | Chloride(s): LaCl3 |
Radius
| Ionic radius (2- ion): pm | Ionic radius (1- ion): pm |
| Atomic radius: 187 pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): pm | Ionic radius (3+ ion): 117.2 pm |
Conductivity
| Thermal conductivity: 13.4 J/m-sec-deg | |
| Electrical conductivity: 14.2 1/mohm-cm | Polarizability: 31.1 A^3 |
Abundance
| Source: Monazite(phosphate), bastnaesite | |
| Rel. abund. solar system: -0.351 log | Abundance earth's crust: 1.5 log |
| cost, pure: 64 $/100g | cost, bulk: $/100g |
