﻿of 
  Atoms 
  and 
  Molecules. 
  871 
  

  

  will, 
  during 
  the 
  process, 
  " 
  repel 
  9 
  * 
  each 
  other. 
  The 
  con- 
  

   sideration 
  offers 
  an 
  explanation 
  of 
  the 
  refusal 
  of 
  helium 
  

   atoms 
  to 
  combine 
  into 
  molecules 
  by 
  a 
  close 
  approach 
  of 
  the 
  

   atoms. 
  

  

  Instead 
  of 
  two 
  hydrogen 
  or 
  two 
  helium 
  atoms, 
  next 
  con- 
  

   sider 
  a 
  hydrogen 
  and 
  a 
  helium 
  atom, 
  and 
  let 
  us 
  slowly 
  

   approach 
  the 
  nuclei 
  to 
  each 
  other 
  in 
  a 
  similar 
  way. 
  In 
  this 
  

   case, 
  contrary 
  to 
  the 
  former 
  cases, 
  the 
  electrons 
  will 
  have 
  no 
  

   tendency 
  to 
  flow 
  together 
  in 
  a 
  single 
  ring. 
  On 
  account 
  of 
  

   the 
  great 
  difference 
  in 
  the 
  radii 
  of 
  the 
  orbits 
  of 
  the 
  electrons 
  

   in 
  hydrogen 
  and 
  helium, 
  the 
  electron 
  of 
  the 
  hydrogen 
  atom 
  

   must 
  be 
  expected 
  to 
  rotate 
  always 
  ontside 
  the 
  helium 
  ring, 
  

   and 
  if 
  the 
  nuclei 
  are 
  brought 
  very 
  close 
  together, 
  the 
  con- 
  

   figuration 
  of 
  the 
  electrons 
  will 
  coincide 
  with 
  that 
  adopted 
  in 
  

   Part 
  II. 
  for 
  a 
  lithium 
  atom. 
  Further, 
  the 
  extraneous 
  forces 
  

   to 
  be 
  applied 
  to 
  the 
  nuclei 
  during 
  the 
  process 
  will 
  be 
  in 
  such 
  

   a 
  direction 
  as 
  to 
  diminish 
  the 
  distance 
  apart. 
  In 
  this 
  way, 
  

   therefore, 
  we 
  cannot 
  obtain 
  a 
  combination 
  of 
  the 
  atoms. 
  

  

  The 
  stable 
  configuration 
  considered 
  in 
  § 
  3, 
  consisting 
  of 
  a 
  

   ring 
  of 
  three 
  electrons 
  and 
  two 
  nuclei 
  of 
  charge 
  e 
  and 
  2e, 
  

   cannot 
  be 
  expected 
  to 
  be 
  formed 
  by 
  such 
  a 
  process, 
  unless 
  

   the 
  ring 
  of 
  electrons 
  were 
  bound 
  originally 
  by 
  one 
  of 
  the 
  

   nuclei. 
  Neither 
  a 
  hydrogen 
  nor 
  a 
  helium 
  nucleus 
  will, 
  

   however, 
  be 
  able 
  to 
  bind 
  a 
  ring 
  of 
  three 
  electrons, 
  since 
  such 
  

   a 
  configuration 
  w 
  T 
  ould 
  correspond 
  to 
  a 
  greater 
  total 
  energy 
  

   than 
  the 
  one 
  in 
  which 
  the 
  nucleus 
  has 
  bound 
  two 
  electrons 
  

   (comp. 
  Part 
  II. 
  pp. 
  488 
  and 
  490). 
  As 
  mentioned 
  in 
  § 
  3, 
  such 
  

   a 
  configuration 
  cannot 
  therefore 
  be 
  considered 
  as 
  representing 
  

   a 
  possible 
  combination 
  of 
  hydrogen 
  and 
  helium, 
  in 
  spite 
  of 
  

   the 
  fact 
  that 
  the 
  value 
  of 
  W 
  is 
  greater 
  than 
  the 
  sum 
  of 
  the 
  

   values 
  of 
  W 
  for 
  a 
  hydrogen 
  and 
  a 
  helium 
  atom. 
  As 
  we 
  

   shall 
  see 
  in 
  the 
  next 
  section, 
  the 
  configuration 
  may, 
  however, 
  

   give 
  indications 
  of 
  the 
  possible 
  structure 
  of 
  the 
  molecules 
  of 
  

   a 
  certain 
  class 
  of 
  chemical 
  combinations. 
  

  

  § 
  5. 
  Systems 
  containing 
  a 
  greater 
  number 
  of 
  Electrons. 
  

  

  From 
  the 
  considerations 
  of 
  the 
  former 
  section 
  we 
  are 
  led 
  

   to 
  indications 
  of 
  the 
  configuration 
  of 
  the 
  electrons 
  in 
  systems 
  

   containing 
  a 
  greater 
  number 
  of 
  electrons, 
  consistent 
  with 
  

   those 
  obtained 
  in 
  § 
  2. 
  

  

  Let 
  us 
  imagine 
  that, 
  in 
  a 
  similar 
  way 
  to 
  that 
  considered 
  

   on 
  p. 
  868 
  for 
  two 
  hydrogen 
  atoms, 
  we 
  make 
  tw 
  r 
  o 
  atoms 
  con- 
  

   taining 
  a 
  large 
  number 
  of 
  electrons 
  approach 
  each 
  other. 
  

   During 
  the 
  beginning 
  of 
  the 
  process 
  the 
  effect 
  on 
  the 
  con- 
  

   figuration 
  of 
  the 
  inner 
  rings 
  will 
  be 
  very 
  small 
  compared 
  

   with 
  the 
  effect 
  on 
  the 
  electrons 
  in 
  the 
  outer 
  rings, 
  and 
  the 
  

  

  