﻿492 
  . 
  Dr. 
  N. 
  Bohr 
  on 
  the 
  Constitution 
  

  

  will 
  not 
  arrange 
  themselves 
  in 
  a 
  single 
  ring 
  and 
  form 
  the 
  

   system 
  : 
  

  

  3(3) 
  a 
  = 
  0"413a 
  , 
  a> 
  = 
  5'87 
  co 
  , 
  W 
  = 
  17-61W 
  , 
  

  

  although 
  W 
  for 
  this 
  configuration 
  is 
  greater 
  than 
  for 
  

   3(2,1). 
  

  

  Since 
  W[3(2,l)]— 
  W[3(2)]=0-89W 
  , 
  we 
  see 
  that 
  the 
  

   outer 
  electron 
  in 
  the 
  configuration 
  3 
  (2. 
  1) 
  is 
  bound 
  even 
  more 
  

   lightly 
  than 
  the 
  electron 
  in 
  a 
  hydrogen 
  atom. 
  The 
  dif- 
  

   ference 
  in 
  the 
  firmness 
  of 
  the 
  binding 
  corresponds 
  to 
  a 
  

   difference 
  of 
  1*4 
  volts 
  in 
  the 
  ionization 
  potential. 
  A 
  marked 
  

   difference 
  between 
  the 
  electron 
  in 
  hydrogen 
  and 
  the 
  outer- 
  

   most 
  electron 
  in 
  lithium 
  lies 
  also 
  in 
  the 
  greater 
  tendency 
  of 
  

   the 
  latter 
  electron 
  to 
  leave 
  the 
  plane 
  of 
  the 
  orbits. 
  The 
  

   quantity 
  Gr 
  considered 
  in 
  § 
  2, 
  which 
  gives 
  a 
  kind 
  of 
  measure 
  

   for 
  the 
  stability 
  for 
  displacements 
  perpendicular 
  to 
  this 
  plane, 
  

   is 
  thus 
  for 
  the 
  outer 
  electron 
  in 
  lithium 
  only 
  0*55, 
  while 
  for 
  

   hydrogen 
  it 
  is 
  1. 
  This 
  may 
  have 
  a 
  bearing 
  on 
  the 
  explana- 
  

   tion 
  of 
  the 
  apparent 
  tendency 
  of 
  lithium 
  atoms 
  to 
  take 
  a 
  

   positive 
  charge 
  in 
  chemical 
  combinations 
  with 
  other 
  

   elements. 
  

  

  For 
  a 
  possible 
  negatively 
  charged 
  lithium 
  atom 
  we 
  may 
  

   expect 
  the 
  configuration 
  : 
  

  

  <2 
  = 
  0'362a 
  &> 
  = 
  7*64ft>o 
  ^ 
  r 
  in 
  . 
  . 
  TT7 
  

  

  3(2,2) 
  1lK1 
  , 
  ° 
  (\.A<ia 
  W=16*16W 
  . 
  

  

  K 
  *> 
  i 
  a 
  = 
  1*516 
  a 
  ew 
  = 
  , 
  43b&) 
  u 
  

  

  It 
  should 
  be 
  remarked 
  that 
  we 
  have 
  no 
  detailed 
  knowledge 
  

   of 
  the 
  properties 
  in 
  the 
  atomic 
  state, 
  either 
  for 
  lithium 
  or 
  

   hydrogen, 
  or 
  for 
  most 
  of 
  the 
  elements 
  considered 
  below. 
  

  

  N 
  = 
  4. 
  Beryllium. 
  

  

  For 
  reasons 
  analogous 
  to 
  those 
  considered 
  for 
  helium 
  and 
  

   lithium 
  we 
  may 
  for 
  the 
  formation 
  of 
  a 
  neutral 
  beryllium 
  atom 
  

   assume 
  the 
  following 
  stages 
  : 
  

  

  4 
  ( 
  i) 
  

  

  a 
  = 
  0'25a 
  

  

  &) 
  = 
  16 
  a> 
  

  

  W 
  = 
  16W 
  , 
  

  

  4 
  ( 
  2) 
  

  

  a 
  = 
  0'267a 
  

  

  a> 
  = 
  14*06 
  a> 
  

  

  W= 
  28-13 
  Wo, 
  

  

  4(2,1) 
  

  

  a 
  1 
  = 
  0'263 
  o 
  

   a 
  2 
  = 
  0*605 
  a 
  

  

  ft)x 
  = 
  14*46 
  ft) 
  

   ft) 
  2 
  = 
  2*74 
  ft) 
  

  

  W=31-65W 
  , 
  

  

  4 
  (2, 
  2) 
  

  

  o 
  1 
  =0-262 
  a 
  

   a 
  2 
  = 
  0*673 
  a 
  Q 
  

  

  ft)j 
  = 
  14*60 
  co 
  

   ft) 
  2 
  = 
  2*21 
  Q> 
  

  

  W 
  =33-61 
  W 
  ; 
  

  

  although 
  the 
  configurations 
  

  

  

  

  4(3) 
  

  

  a=0-292a 
  

  

  ft) 
  = 
  ll*71 
  ft) 
  

  

  W 
  = 
  35*14 
  W 
  , 
  

  

  4(4) 
  

  

  a 
  = 
  0'329a 
  

  

  &)= 
  9*26 
  ft) 
  

  

  W 
  = 
  37-04 
  W 
  , 
  

  

  