Name: Lanthanum
Symbol: La
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)
Number of Protons/Electrons: 57
Number of Neutrons: 82
Crystal Structure: Hexagonal
Density @ 293 K: 6.7 g/cm3
Color: white
Atomic Structure
![[Bohr Model of Lanthanum]](b0057.gif) |
Number of Energy Levels: 6 First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 18 Fourth Energy Level: 18 Fifth Energy Level: 9 Sixth Energy Level: 2 |
Isotopes
| Isotope | Half Life |
| La-134 | 6.5 minutes |
| La-137 | 6000.0 years |
| La-138 | 1.05E10 years |
| La-139 | Stable |
| La-140 | 1.67 days |
| La-141 | 3.9 hours |
| La-142 | 1.54 minutes |
Facts
Date of Discovery: 1839Discoverer: Carl Mosander
Name Origin: From the Greek word lanthaneis (to lie hidden)
Uses: expensive camera lenses
Obtained From: monazite, bastnasite
Information provided by: http://www.chemicalelements.com