 |
| Date of Discovery: |
1839 |
| Discoverer: |
Carl Mosander |
| Name Origin: |
From the Greek word lanthaneis (to lie hidden) |
| Uses: |
expensive camera lenses |
| Obtained From: |
monazite, bastnasite |
| Atomic Number: |
57 |
| Atomic Mass: |
138.9055 amu |
| Melting Point: |
920.0 °C (1193.15 °K, 1688.0 °F) |
| Boiling Point: |
3469.0 °C (3742.15 °K, 6276.2 °F) |
| Crystal Structure: |
Hexagonal |
| Density @ 293 K: |
6.7 g/cm3 |
| Color: |
white |
| Isotope |
La-134 |
La-137 |
La-138 |
La-139 |
La-140 |
La-141 |
La-142 |
| Half Life |
6.5 min
|
6000.0 years
|
1.05E10 years |
Stable |
1.67 days |
3.9 hours |
1.54 min |
|
