EXPLORING THE ATOM 



As most solid substances can be reduced to the gas- 

 eous condition in known proportions, the number of 

 atoms in a given quantity of any solid may also be 

 quite generally computed. 



The figures revealed are utterly bewildering. Pro- 

 fessor Rutherford found that a grain of radium gives 

 off 36 billion helium atoms per second. A cubic 

 centimeter of helium gas contains atoms to a num- 

 ber represented by this absurd row of figures: 

 2,560,000,000,000,000,000,000 which is read, I be- 

 lieve, two sextillion, five hundred and sixty quintil- 

 lion. 



The weight of a single atom is the part of a gram 

 represented by a fraction having one for the numer- 

 ator and for denominator 68 followed by 24 ciphers 

 carrying the count to octillions. 



Of course such figures convey little definite mean- 

 ing. Perhaps they serve, however, to give at least 

 an inkling of the utterly incomprehensible smallness 

 of an atom. Reflecting, then, that the electroscope 

 is able to detect the presence of a single one of these 

 atoms, we find ourselves in the presence of an instru- 

 ment the delicacy of whose operation is little less 

 than awe-inspiring. 



We saw that the big telescopes, aided by the pho- 

 tographic plate, reveal stars to the number of at 

 least one hundred million lying utterly beyond the 

 confines of unaided vision. Now it appears that a 

 pinch of salt that one could hold on the point of a 

 penknife is made up of atoms numbering not hun- 

 dreds of millions merely, but billions of billions. The 

 population of atoms in the smallest particle of mat- 



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