Physical Properties of Rubidium and Tantalum
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Grayish White
  
Gray Blue
  
Luster
NA
  
Metallic
  
Hardness
  
  
Vickers Hardness
Not Available
  
Speed of Sound
1,300.00 m/s
  
99+
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