Electron Theory of Chemistry to Solids. 737 



the solid into a monatomic £as i s neo-lectino- the difference 



in the specific heats, 



A l/3 : " 

 ^1-24 — 



If M' is the atomic weight of the atom whose mass is M, 

 M = M'xl-64xlO- 24 , 

 and the preceding expression becomes, 



The energy l-S25e 2 /d possessed by an atom in the 

 solid state with its electron is eqcnl to that acquired by a 



/ A V'' 3 

 charge e falling through 21*25 I M , J volts. 



Latent Heat of Fusion of Monovalent Elements. 



If the energy per atom in the liquid state is greater than 

 that in the solid the transformation of each atom from the 

 solid to the liquid state will involve the expenditure of a 

 definite amount of energy. This, when there is no difference 

 in the specific heats for the two states, will be a measure of 

 the latent heat of fusion. 



The energy per atom when these are at the centres of 

 cubes whose edge is d is represented by 



-1-82. J; 



if M' is the atomic weight and A the density, this is equal to 



/ A \V3 

 -34.10-(^) ; 



the energy per gramme is 



20-7 xlO 12 / AV/3 



M' 



/ A V' 3 



{w) ! < 9 > 



hence if A / is the density in the liquid state, the difference 

 in energy between one gramme of solid and one of liquid is 



20-7 x 10 12 f / A Y' 3 _ / A' \ 1/3 1 



For potassium M' = 39, the values of A, A', as determined 

 Phil. Mag. S. 6. Vol. 43. No. 256. April 1922. 3 B 



