318 



Prof. W. D. Harkins 



the 



Table IV. 



Abundance or the Atomic Species in the Earth's Crust as 

 Classified according to their Isotopic and Class Numbers. 



Isotopic Number 



=0. 











(N/P=0-5.) 





Isotopic Numbei 



= 1. 



Class 



Number 



=1. 



Class 



Number : 



= 11. 



Atomic 







Atomic 







Number. 



Symbol. 



Per cent. 



Number. 



Symbol. 



Per cent. 



6 



C 



0047 



3 



Li 7 



0-009 



8 







61-94 



5 



B u 





12 



Mg M 



T40 



9 



F 



0-086 



14 



Si 28 



1906 



11 



Na 



2-64 



16 



s 



0034 



13 



Al 



6-43 



20 



Ca 



1-93 



15 



P 



089 



26 



Fe 52 



9 



17 



CI 35 



0-025 



28- 



Ni 56 



? 



19 



Total. 



K 



1-42 



Total 



84-41 



. 10-70 



Class 



Number = 



-•TV. 









3 



Li 6 



0-0005 



Class Number = 



III. 



5 



B 10 



... 



12 



Mg 25 



0-22 



7 . 



N 



... 



14 

 Total. 



Si 29 



2-04(?) 



Total 



- 00005 



.. 2-26 



Isotopic Number=2. 

 Class Number =1. 



Isotopic Number =3. 

 Class Number =11. 



Atomic 

 Number. 



12 



14 



26 



28 



Symbol. 

 Mg 2C 

 Si 30 

 (Fe 54 ) 

 (Ni") 



Per cent. 

 0-21 



V 



? 



9 







Atomic 

 Nnmber. 



17 



21 



Total 



Symbol. 

 CI 37 

 Sc 



Per cent. 

 0-007 



o-ooooo 



... 0-007 



Total. 



... 0-21 





Isotopic Number =4*. 

 Class Number =1. 

 Atomic 



Number. Symbol. Per cent. 

 22 Ti 0-28 

 24 Cr 0017 

 26 Fe 56 1-88 

 28 Ni 60 0-01 • 

 30 Zn 64 0000 



Isotoj 



Class 



Atomic 

 Number. 



17 

 23 

 25 

 27 

 29 



Total 



)ic Num 

 Numbe 



Symbol 

 CI 39 

 V 

 Mn 

 Co 

 Cu 



ber=5. 

 r = II. 



. Per cent. 



0-009 

 0037 

 0000 

 0-0006 (?) 



0-047 



Isoto 



Clas 



Atomic 



Number. 



30 



32 



36 



pic Number =6. 

 3 Number =11. 



Symbol. Per cent. 

 (Zn 66 ) (0-OOOOr?) 



(Ge 7 °) 



Kr 78 



Total 



. 2-19 











* It should be noted that in Isotopic number 4 the relations of Isotopic 

 number are repeated, but with a much smaller abundance. Thus both have 

 a high abundance relative to the adjacent atomic numbers; in both Class I. is 

 prominent, and while Class IV. has-not yet been found in Isotopic number 4, 

 it may be present, but only in a very minute quantity. Isotopic number 5 

 repeats in a lesser degree the relations of Isotopic number 1, again with the 

 omission of the secondary class, Class III. While the numbers given in the 

 Table may be changed slightly in a few cases by the discovery of new isotopes, 

 the atomic weight and abundance relations indicate that stick changes will not 

 affect the general relations presented. 



