206 Dr. Marshall Waits on a Relationship 



Example 3. From the atomic weight of indium, 113*7, to 

 calculate that of gallium (69*9"). 



The following lines are assumed to correspond : — 



Indium. Gallium. 



(«) 22159-3 10 r 23961-1 20 r 



(ft) 24371-8 Sr 24787-3 10 r 



(a) & (ft) give 69-47. 



(e) 30701-5 10;- 339541 In 



(d) 32890-5 10 r 34780-8 '2n 



(c) & (d) give 69-87. 



Example 4. From the atomic weight o£ barium, 136*76, 

 and that of calcium, 39" 99, to calculate the atomic weight of 

 strontium (87*37). 



The lines assumed to correspond are : — 





Barium. 





Strontium. 





Ca]eium. 





(a) 



15387 



6r 



19388 



10 



21617 



1/. 



(6) 



17873 



4// 



22061 



6 



24390 



4ft 



(c) 



21951 



lOr 



26976 



6 a 



29736 



8ft 



(d) 



22979 



Sr 



28177 



()W 



30991 



4ft 



(e) 



24201 



8r 



29399 



\n 



32229 



1/2 



From (a) we get 87 - 85 for the atomic weiglit of strontium, 

 (ft) 87-82 



(c) 87-54 



(d) 87-22 



(e) 87-34 



Example 5. From the atomic weight of caBsium, 132*7, and 

 that of potassium to calculate the atomic weight of rubidium 

 (85*2). 



The following lines are assumed to correspond : — 



Caesium. Rubidium. Potassium, 



(a) 12469 6 13742 4 14465 7 



(ft) 21764 6r 23714 6r 24700 6/ 



(c) 21945 8r 23791 8r 24719 8? 



(d) 25707 4r 27833 4r 28998 6r 



(e) 25787 6r 27868 6r 29006 8r 

 (/) 27638 2/' 29832 2r 31068 4r 

 (^ 27678 4r 29852 4r 31073 6r 



{«) gives 86-87 



(ft) ' 83-24 



(c) 83-11 



(tf) 84-51 



(e) 84-93 



f /") 85-52 



(r/) 85-51 



