Praseodymium at Chemical Elements.com 


 

Basic Information


Name: Praseodymium
Symbol: Pr
Atomic Number: 59
Atomic Mass: 140.90765 amu
Melting Point: 935.0 °C (1208.15 °K, 1715.0 °F)
Boiling Point: 3127.0 °C (3400.15 °K, 5660.6 °F)
Number of Protons/Electrons: 59
Number of Neutrons: 82
Classification: Rare Earth
Crystal Structure: Hexagonal
Density @ 293 K: 6.77 g/cm3
Color: Unknown


Atomic Structure

[Bohr Model of Praseodymium]  
Number of Energy Levels: 6

    First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 18
    Fourth Energy Level: 21
    Fifth Energy Level: 8
    Sixth Energy Level: 2

Isotopes

Isotope Half Life
Pr-141 Stable
Pr-142 19.12 hours
Pr-143 13.57 days
Pr-144 17.28 minutes
Pr-145 7.2 minutes

Facts


Date of Discovery: 1885
Discoverer: C.F. Aver von Welsbach
Name Origin: From the Greek words prasios (green) and didymos (twin)
Uses: coloring glass and ceramics
Obtained From: salts