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Information valid for Pr-141 unless otherwise noted

Basic Information

Symbol: Pr
Atomic Number: 59
Mass: 140.90765
Melting Point: 935.0 C
Boiling Point: 3127.0 C
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

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


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


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