4 STROMEYER, Grouping of Chemical Elements. 



Elements. 



Atomic 

 Weights. 



Group 

 Position. 



Calculated 

 At. Wt. 



Difference. 



Group I. 



Mean position, 1-04. 



Lithium ... 

 Potassium 

 Rubidium 

 Caesium... 



Li 

 K 

 Rb 

 Cs 



7'°3 



39 -1 5 

 85-40 



132-90 



1-14 

 0-87 

 1-13 

 1-64 



39'59 

 85-I7 



+ 0-23 

 -0-44 



+ 0-23 

 + 1-85 



Group II. 



Mean position, 1-72. 



Calcium 



Be or Gl 

 Ca 

 Sr 

 Ba 



Ra 



9-10 



40T0 



87-60 



i37'4o 



225-00 



1-96 

 1-23 

 1-97 

 3^3 



2-82 



8-49 



4i"37 



86-91 

 133-20 



22174 



+ 061 

 - 1-27 

 + 69 



+ 4-20 



+ 3-26 



Strontium 



Barium 



Radium 





Group III. 



Mean position, 2 -66. 



Boron 



Scandium .. 



Yttrium 



Lanthanum 

 Ytterbium .. 



B 



Sc 

 Y 

 La 

 Yb 



44-10 



89-00 



138-90 



173-00 



279 



2 69 



2-50 



3 '64 



0-03 



io-68 



44-08 



8944 



136-10 



l8o , 2'? 



+ 0-32 



+ - 02 



-°'44 

 + 2-80 



-7-23 



