Basic Information

Name: Thorium 
Symbol: Th 
Atomic Number: 90 
Atomic Mass: 232.0381 amu 
Melting Point: 1750.0 °C (2023.15 K, 3182.0 °F) 
Boiling Point: 4790.0 °C (5063.15 K, 8654.0 °F) 
Number of Protons/Electrons: 90 
Number of Neutrons: 142 
Classification: Rare Earth 
Crystal Structure: Cubic 
Density @ 293 K: 11.72 g/cm3 
Color: silvery
Date of Discovery: 1828 
Discoverer: Jons Berzelius 
Name Origin: Thor (Scandinavian god) 
Uses: strong alloys, ultraviolet photoelectric cells 
Obtained From: monazite, thorite