﻿Frequency 
  and 
  Molecular 
  Number. 
  449 
  

  

  Rubidium 
  Compounds 
  (N 
  = 
  37). 
  

  

  Name. 
  Formula. 
  N. 
  vXlO 
  -12 
  . 
  N^xlO 
  -12 
  - 
  

   Rubidium 
  

  

  bromide 
  EbBr 
  72 
  1-990 
  7 
  x205 
  

  

  chloride 
  (a) 
  RbCl 
  54- 
  2310 
  6x20-8 
  

  

  fluoride 
  EbF 
  46 
  3021 
  6&X21-4 
  

  

  hydroxide 
  EbOH 
  46 
  2297 
  5 
  X211 
  

  

  iodide 
  Ebl 
  90 
  1616 
  7x20-8 
  

  

  oxidedi- 
  Eb.,0 
  2 
  90 
  1674 
  7 
  x21'5 
  

  

  pentasulphide 
  Eb 
  2 
  S 
  5 
  154 
  0'685 
  5 
  x2M 
  

  

  (a) 
  Melting-point 
  of 
  rubidium 
  chloride, 
  714° 
  C. 
  (Eichards&Meldrum, 
  1917). 
  

  

  Caesium 
  Compounds 
  (X 
  = 
  55). 
  

   Cesium 
  

  

  chloride 
  (a) 
  CsCl 
  72 
  2065 
  7 
  X212 
  

  

  iodide 
  Csl 
  108 
  1-480 
  7£X213 
  

  

  nitrate 
  CsX0 
  3 
  86 
  1542 
  6^x20-4 
  

  

  oxide 
  tri- 
  Cs 
  2 
  3 
  134 
  1-076 
  7~X206 
  

  

  „ 
  tetr- 
  Ce 
  2 
  4 
  142 
  1-073 
  7*X20"3 
  

  

  pentasulphide 
  Cs 
  2 
  S 
  5 
  190 
  0612 
  5^X21*1 
  

  

  (a) 
  Melting-point 
  of 
  caesium 
  chloride, 
  645° 
  C. 
  (Richards 
  & 
  Meldrum, 
  1917). 
  

  

  Only 
  a 
  few 
  copper 
  compounds 
  can 
  be 
  included 
  ; 
  it 
  is 
  of 
  

   interest 
  to 
  note 
  that 
  the 
  frequency 
  number 
  for 
  cupric 
  

   chloride 
  is 
  6| 
  as 
  compared 
  with 
  6 
  for 
  the 
  cuprous 
  salt. 
  

  

  Copper 
  Compounds 
  (N 
  = 
  29). 
  

  

  Name. 
  Formula. 
  N. 
  rXlO 
  -12 
  . 
  NvXlO 
  -12 
  . 
  

   Cuprous 
  

  

  bromide 
  CuBr 
  64 
  2267 
  7 
  X20-7 
  

  

  chloride 
  CuCl 
  46 
  2-726 
  6 
  X20-9 
  

  

  iodide 
  Cul 
  82 
  2048 
  8 
  x21"0 
  

  

  sulphide 
  Cu 
  2 
  S 
  74 
  3-002 
  11 
  x20"2 
  

  

  chloride 
  CuCl 
  2 
  63 
  2136 
  6^x207 
  

  

  oxide 
  CuO 
  37 
  5-458 
  10 
  x202 
  

  

  Silver 
  Compounds 
  (N 
  = 
  47). 
  

   Silver 
  

  

  bromide 
  AgBr 
  82 
  1935 
  7*x21'2 
  

  

  chlorate 
  AgC10 
  3 
  88 
  1421 
  6 
  x208 
  

  

  chloride 
  AgCl 
  64 
  2"343 
  7 
  X21-4 
  

  

  fluoride 
  AgF 
  56 
  2609 
  7 
  X21-0 
  

  

  iodide 
  Agl 
  100 
  1"657 
  8 
  X207 
  

  

  nitrate 
  (a) 
  AgN0 
  3 
  78 
  1*543 
  6 
  X201 
  

  

  phosphate 
  ortho 
  Ag 
  3 
  P0 
  4 
  188 
  1-309 
  15 
  x206 
  

  

  pyro 
  Ag 
  4 
  P 
  o 
  0_ 
  274 
  0-756 
  10 
  x20"7 
  

  

  sulphate 
  Ag 
  2 
  S0 
  4 
  ' 
  142 
  1'378 
  Six20-8 
  

  

  sulphide 
  Ag 
  2 
  S 
  110 
  2004 
  10|x210 
  

  

  telluride 
  Ag 
  2 
  Te 
  146 
  1686 
  12 
  x205 
  

  

  (a) 
  Silver 
  nitrate 
  changes 
  from 
  the 
  rhombic 
  to 
  the 
  hexagonal-rhombo- 
  

   bedric 
  form 
  at 
  159°-8 
  C. 
  The 
  density 
  of 
  the 
  rhombic 
  form 
  has 
  been 
  

   used 
  in 
  the 
  calculation. 
  

  

  The 
  salts 
  of 
  silver 
  show 
  fair 
  agreement 
  with 
  the 
  proposed 
  

   relation. 
  It 
  is 
  doubtful 
  whether 
  silver 
  nitrate 
  should 
  have 
  

  

  