Thermal Properties of Neptunium and Promethium
Specific Heat
0.12 J/(kg K)
  
40
0.18 J/(kg K)
  
33
Molar Heat Capacity
29.46 J/mol·K
  
8
Not Available
  
Thermal Conductivity
6.30 W/m·K
  
99+
17.90 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
Not Available
  
9.00 µm/(m·K)
  
99+
Enthalpy
  
  
Enthalpy of Fusion
3.20 kJ/mol
  
99+
7.50 kJ/mol
  
99+
Enthalpy of Atomization
Not Available
  
310.00 kJ/mol
  
34
Standard Molar Entropy
Not Available
  
Not Available