﻿410 
  E. 
  A. 
  Hill— 
  Argon, 
  Front's 
  

  

  If 
  the 
  views 
  outlined 
  are 
  correct 
  then 
  the 
  following 
  rela- 
  

   tions 
  ought 
  to 
  hold 
  at 
  least 
  in 
  Mendeleeffs 
  short 
  periods.* 
  

  

  Groups 
  I 
  and 
  Groups 
  III, 
  IV, 
  

   Properties, 
  etc. 
  VII. 
  VIII. 
  

  

  Atomic 
  volume 
  »_ 
  _ 
  large 
  small 
  

  

  Tendency 
  toward 
  internal 
  energy 
  of 
  

  

  rotation 
  " 
  " 
  

  

  Tendency 
  to 
  combine 
  directly 
  with 
  other 
  

  

  elements 
  " 
  " 
  

  

  Heat 
  absorbed 
  in 
  separating 
  atom 
  from 
  

  

  atom 
  (dissociation) 
  small 
  large 
  

  

  Heat 
  of 
  formation 
  in 
  solution 
  " 
  " 
  

  

  Distance 
  between 
  the 
  atoms 
  in 
  the 
  mole- 
  

   cule 
  __ 
  large 
  small 
  

  

  Force 
  of 
  attraction 
  for 
  the 
  atoms 
  of 
  

  

  other 
  molecules 
  " 
  " 
  

  

  Distance 
  between 
  the 
  atoms 
  of 
  different 
  

  

  molecules 
  small 
  large 
  

  

  Force 
  of 
  attraction 
  between 
  atoms 
  in 
  the 
  

  

  same 
  molecule 
  . 
  _ 
  . 
  " 
  " 
  

  

  How 
  far 
  does 
  this 
  scheme 
  of 
  properties 
  conform 
  to 
  nature 
  ? 
  

   In 
  the 
  two 
  short 
  periods 
  Li— 
  F 
  and 
  Na— 
  CI 
  the 
  atomic 
  volume 
  

   (distance 
  between 
  the 
  atoms) 
  decreases 
  from 
  alkali 
  Group 
  I 
  to 
  

   Carbon 
  Group 
  IV, 
  and 
  then 
  increases 
  from 
  Nitrogen 
  Group 
  V 
  

   to 
  Group 
  VII 
  the 
  Halogens. 
  We 
  are 
  ignorant 
  of 
  the 
  amount 
  

   of 
  internal 
  energy 
  of 
  rotation 
  in 
  Groups 
  I, 
  II, 
  III 
  and 
  IY 
  but 
  

   we 
  have 
  in 
  Groups 
  V, 
  JSP=1'82, 
  in 
  VI, 
  2 
  =1'96, 
  and 
  in 
  VII, 
  

   Cl 
  2 
  = 
  3*84. 
  These 
  values 
  show 
  the 
  constant 
  increase 
  which 
  the 
  

   theory 
  requires. 
  

  

  That 
  the 
  tendency 
  for 
  direct 
  combination 
  with 
  other 
  ele- 
  

   ments 
  is 
  a 
  maximum 
  in 
  Group 
  I 
  decreases 
  to 
  Group 
  IV 
  and 
  

   then 
  increases 
  again 
  to 
  Group 
  VII 
  is 
  too 
  well 
  known 
  to 
  require 
  

   illustration. 
  

  

  * 
  Just 
  as 
  this 
  article 
  is 
  going 
  to 
  press 
  I 
  note 
  the 
  following 
  remarks 
  made 
  by 
  

   Mendeleeff, 
  March 
  14th, 
  before 
  the 
  Russian 
  Chemical 
  Society: 
  

  

  "In 
  favor 
  of 
  this 
  supposition 
  (monatomicity) 
  we 
  have 
  the 
  specific 
  heat 
  ratio 
  at 
  

   constant 
  volumes 
  and 
  pressures, 
  K, 
  found 
  by 
  Rayleigh 
  and 
  Ramsay, 
  to 
  be 
  near 
  

   to 
  1*66, 
  i.e. 
  to 
  the 
  value 
  which 
  is 
  considered 
  as 
  characteristic 
  for 
  monatomic 
  gases. 
  

   It 
  must 
  however 
  be 
  borne 
  in 
  mind 
  that 
  K 
  varies 
  for 
  compound 
  molecules, 
  even 
  

   when 
  these 
  last 
  contain 
  the 
  same 
  number 
  of 
  atoms 
  ; 
  thus 
  for 
  most 
  bivalent 
  gases 
  

   (nitrogen, 
  oxygen, 
  etc.) 
  K 
  is 
  near 
  to 
  1*4, 
  while 
  for 
  chlorine 
  it 
  is 
  1*3. 
  This 
  last 
  

   figure 
  makes 
  one 
  think 
  that 
  K 
  depends 
  not 
  only 
  upon 
  the 
  number 
  of 
  atoms 
  in 
  the 
  

   molecule, 
  but 
  also 
  upon 
  chemical 
  energy, 
  that 
  is 
  upon 
  the 
  stock 
  of 
  internal 
  

   motion 
  which 
  determines 
  the 
  chemical 
  activity 
  of 
  a 
  body 
  and 
  the 
  quantity 
  of 
  

   which 
  must 
  be 
  relatively 
  great 
  with 
  chlorine. 
  If, 
  with 
  the 
  chemically 
  active 
  

   chlorine, 
  K 
  is 
  notably 
  less 
  than 
  1-4, 
  we 
  may 
  admit 
  that 
  for 
  the 
  inactive 
  argon 
  it 
  

   is 
  much 
  more 
  than 
  1'4, 
  even 
  though 
  the 
  molecule 
  of 
  argon 
  may 
  contain 
  two 
  or 
  

   more 
  atoms." 
  

  

  Mendeleeff 
  seems 
  to 
  lean 
  toward 
  the 
  view 
  that 
  Argon 
  is 
  N 
  3 
  though 
  prefers 
  an 
  

   atomic 
  weight 
  of 
  20 
  to 
  one 
  of 
  40 
  if 
  it 
  be 
  a 
  new 
  element. 
  

  

  