Physical Properties of Roentgenium and Tantalum
Melting Point
Not Available
  
Boiling Point
Not Available
  
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Gray Blue
  
Luster
Unknown Luster
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
Vickers Hardness
Not Available
  
Speed of Sound
Not Available
  
3,400.00 m/s
  
22
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available