Physical Properties of Thorium and Niobium
Melting Point
1,750.00 °C
  
17
Boiling Point
2,468.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Gray
  
Luster
NA
  
Metallic
  
Hardness
  
  
Speed of Sound
2,490.00 m/s
  
36
3,480.00 m/s
  
21
Optical Properties
  
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available