Name: Promethium
Symbol: Pm
Atomic Number: 61
Atomic Mass: (145.0) amu
Melting Point: Unknown
Boiling Point: Unknown
Number of Protons/Electrons: 61
Number of Neutrons: 84
Crystal Structure: Hexagonal
Density @ 293 K: 6.475 g/cm3
Color: Unknown
Atomic Structure
![[Bohr Model of Promethium]](b0061.gif) |
Number of Energy Levels: 6 First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 18 Fourth Energy Level: 23 Fifth Energy Level: 8 Sixth Energy Level: 2 |
Isotopes
| Isotope | Half Life |
| Pm-143 | 265.0 years |
| Pm-144 | 360.0 years |
| Pm-145 | 17.7 years |
| Pm-146 | 5.53 years |
| Pm-147 | 2.62 years |
| Pm-148 | 5.37 days |
| Pm-148m | 41.3 days |
| Pm-149 | 2.21 days |
| Pm-151 | 1.18 days |
Facts
Date of Discovery: 1945
Discoverer: J.A. Marinsky
Name Origin: From the god Prometheus (who stole fire of the sky and gave it to man)
Uses: No uses known
Obtained From: fission products of uranium, thorium, plutonium
Information provided by: http://www.chemicalelements.com