﻿of 
  Atoms 
  and 
  Molecules. 
  495 
  

  

  The 
  above 
  considerations 
  may 
  be 
  taken 
  as 
  an 
  indication 
  

   that 
  there 
  is 
  a 
  greater 
  tendency 
  for 
  the 
  confluence 
  o£ 
  two 
  

   rings 
  when 
  each 
  contains 
  the 
  same 
  number 
  of 
  electrons- 
  

   Considering 
  the 
  successive 
  binding 
  of 
  electrons 
  by 
  a 
  positive 
  

   nucleus, 
  we 
  conclude 
  from 
  this 
  that, 
  unless 
  the 
  charge 
  on 
  

   the 
  nucleus 
  is 
  very 
  great, 
  rings 
  of 
  electrons 
  will 
  only 
  join 
  

   together 
  if 
  they 
  contain 
  equal 
  numbers 
  o£ 
  electrons; 
  and 
  

   that 
  accordingly 
  the 
  numbers 
  of 
  electrons 
  on 
  inner 
  rings 
  

   will 
  only 
  be 
  2, 
  4, 
  8, 
  ... 
  . 
  If 
  the 
  charge 
  of 
  the 
  nucleus 
  is 
  

   very 
  great 
  the 
  rings 
  of 
  electrons 
  first 
  bound, 
  if 
  few 
  in 
  

   number, 
  will 
  be 
  very 
  close 
  together, 
  and 
  we 
  must 
  expect 
  

   that 
  the 
  configuration 
  will 
  be 
  very 
  unstable, 
  and 
  that 
  a 
  

   gradual 
  interchange 
  of 
  electrons 
  between 
  the 
  rings 
  will 
  be 
  

   greatly 
  facilitated. 
  

  

  This 
  assumption 
  in 
  regard 
  to 
  the 
  number 
  of 
  electrons 
  in 
  

   the 
  rings 
  is 
  strongly 
  supported 
  by 
  the 
  fact 
  that 
  the 
  chemical 
  

   properties 
  of 
  the 
  elements 
  of 
  low 
  atomic 
  weight 
  vary 
  with 
  a 
  

   period 
  of 
  8. 
  Further, 
  it 
  follows 
  that 
  the 
  number 
  of 
  electrons 
  

   on 
  the 
  outermost 
  ring 
  will 
  always 
  be 
  odd 
  or 
  even, 
  according 
  

   as 
  the 
  total 
  number 
  of 
  electrons 
  in 
  the 
  atom 
  is 
  odd 
  or 
  even. 
  

   This 
  has 
  a 
  suggestive 
  relation 
  to 
  the 
  fact 
  that 
  the 
  valencv 
  of 
  

   an 
  element 
  of 
  low 
  atomic 
  weight 
  always 
  is 
  odd 
  or 
  even 
  

   according 
  as 
  the 
  number 
  of 
  the 
  element 
  in 
  the 
  periodic 
  

   series 
  is 
  odd 
  or 
  even. 
  

  

  For 
  the 
  atoms 
  of 
  the 
  elements 
  considered 
  in 
  the 
  former 
  

   section 
  we 
  have 
  assumed 
  that 
  the 
  two 
  electrons 
  first 
  bound 
  

   are 
  arranged 
  in 
  a 
  single 
  ring, 
  and, 
  further, 
  that 
  the 
  two 
  next 
  

   electrons 
  are 
  arranged 
  in 
  another 
  ring. 
  If 
  N 
  > 
  4 
  the 
  con- 
  

   figuration 
  N 
  (4) 
  will 
  correspond 
  to 
  a 
  smaller 
  value 
  for 
  the 
  

   total 
  energy 
  than 
  the 
  configuration 
  N 
  (2,2). 
  The 
  greater 
  the- 
  

   value 
  of 
  X 
  the 
  closer 
  will 
  the 
  ratio 
  between 
  the 
  radii 
  of 
  

   the 
  rings 
  in 
  the 
  configuration 
  N(2, 
  2) 
  approach 
  unity, 
  and 
  

   the 
  greater 
  will 
  be 
  the 
  energy 
  emitted 
  bv 
  an 
  eventual 
  con- 
  

   fluence 
  of 
  the 
  rings. 
  The 
  particular 
  member 
  of 
  the 
  series 
  

   of 
  the 
  elements 
  for 
  which 
  the 
  four 
  innermost 
  electrons 
  will 
  

   be 
  arranged 
  for 
  the 
  first 
  time 
  in 
  a 
  single 
  ring 
  cannot 
  bo 
  

   determined 
  from 
  the 
  theory. 
  From 
  a 
  consideration 
  of 
  the 
  

   chemical 
  properties 
  we 
  can 
  hardly 
  expect 
  that 
  it 
  will 
  have 
  

   taken 
  place 
  before 
  boron 
  (N 
  = 
  5) 
  or 
  carbon 
  (N 
  = 
  6), 
  on 
  

   account 
  of 
  the 
  observed 
  trivalency 
  and 
  tetravalency 
  respec- 
  

   tively 
  of 
  these 
  elements 
  ; 
  on 
  the 
  other 
  hand, 
  the 
  periodic 
  

   svstem 
  of 
  the 
  elements 
  strongly 
  suggests 
  that 
  already 
  in 
  neon 
  

   (N 
  = 
  10) 
  an 
  inner 
  ring 
  of 
  eight 
  electrons 
  will 
  occur. 
  Unless 
  

   N2L14 
  the 
  configuration 
  N 
  (4,4) 
  corresponds 
  to 
  a 
  smaller 
  value 
  

   for 
  the 
  total 
  energy 
  than 
  the 
  configuration 
  N(8) 
  ; 
  already 
  

  

  2 
  L 
  2 
  

  

  