Physical Properties of Protactinium and Iron
Melting Point
1,568.00 °C
  
21
1,535.00 °C
  
25
Boiling Point
4,027.00 °C
  
12
2,750.00 °C
  
37
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Gray
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
Vickers Hardness
Not Available
  
Speed of Sound
Not Available
  
5,120.00 m/s
  
8
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
No
  
Yes
  
α Allotropes
Not Available
  
Ferrite (alpha Iron)
  
β Allotropes
Not Available
  
beta Iron
  
γ Allotropes
Not Available
  
gamma Iron