The solar composition (strictly speaking the primordial solar nebular composition) is somewhat
controversial these days (circa 2006)---all that worry about neon and so on.
Here we just give the composition of Asplund et al. (2005)
which is probably not the last word.
A plot of solar composition in mass fraction is given below. Below the plot is a table with number fraction (normalized to Si at 1.e+6) and mass fraction.
The fiducial atomic weights are just the round-to-integer atomic weight of most abundant solar isotope. The solar atomic weights are solar composition average more or less I assume. The solar atomic weights are from Wolfson and Pasachoff, except the H and He weights are the H-1 and He-4 weights from Enge (p. 528). I'd rather use those than mix in the other isotopes of H and He. I never finished typing these numbers in. I should probably get good values from somewhere sometime. But the fiducial atomic weight are probably good for supernovae where the actual isotopic average is uncertain.
Postscript plot of the solar composition.
Element At.No. Fiducial At.Wt. Solar At.Wt. No. Frac. Mass Frac.
H 1. 1. 1.007825 1.000E+12 7.334E-01
He 2. 4. 4.002603 8.511E+10 2.497E-01
Li 3. 7. 6.941000 2.042E+03 1.048E-08
Be 4. 9. 9.012000 2.630E+01 1.736E-10
B 5. 11. 10.810000 6.166E+02 4.974E-09
C 6. 12. 12.010000 3.311E+08 2.914E-03
N 7. 14. 14.010000 8.318E+07 8.540E-04
O 8. 16. 16.000000 6.761E+08 7.933E-03
F 9. 19. 19.000000 3.020E+04 4.208E-07
Ne 10. 20. 20.180000 1.202E+08 1.763E-03
Na 11. 23. 22.990000 2.089E+06 3.524E-05
Mg 12. 24. 24.310000 3.802E+07 6.692E-04
Al 13. 27. 26.980000 3.090E+06 6.119E-05
Si 14. 28. 28.090000 3.631E+07 7.456E-04
P 15. 31. 30.970000 3.631E+05 8.255E-06
S 16. 32. 32.070000 1.585E+07 3.720E-04
Cl 17. 35. 35.450000 1.905E+05 4.891E-06
Ar 18. 40. 39.950000 2.512E+06 7.369E-05
K 19. 39. 39.100000 1.349E+05 3.858E-06
Ca 20. 40. 40.080000 2.239E+06 6.567E-05
Sc 21. 45. 44.960000 1.259E+03 4.155E-08
Ti 22. 48. 47.880000 8.710E+04 3.066E-06
V 23. 51. 50.940000 1.047E+04 3.917E-07
Cr 24. 52. 52.000000 4.898E+05 1.868E-05
Mn 25. 55. 54.940000 3.388E+05 1.367E-05
Fe 26. 56. 55.850000 3.162E+07 1.299E-03
Co 27. 59. 58.930000 8.128E+04 3.517E-06
Ni 28. 59. 58.690000 1.778E+06 7.695E-05
Cu 29. 64. 63.550000 1.950E+04 9.152E-07
Zn 30. 65. 65.390000 4.677E+04 2.230E-06
Ga 31. 70. 69.720000 1.349E+03 6.925E-08
Ge 32. 73. 72.610000 4.266E+03 2.284E-07
As 33. 75. 74.920000 2.344E+02 1.289E-08
Se 34. 79. 78.960000 2.570E+03 1.489E-07
Br 35. 80. 79.900000 4.266E+02 2.503E-08
Kr 36. 84. 83.800000 2.042E+03 1.258E-07
Rb 37. 85. 85.470000 2.570E+02 1.602E-08
Sr 38. 88. 87.620000 8.318E+02 5.368E-08
Y 39. 89. 88.910000 1.698E+02 1.108E-08
Zr 40. 91. 91.220000 4.074E+02 2.719E-08
Nb 41. 93. 93.000000 2.512E+01 1.713E-09
Mo 42. 96. 96.000000 9.333E+01 6.571E-09
Tc 43. 99. 99.000000 1.000E-30 7.261E-41
Ru 44. 101. 101.000000 6.761E+01 5.008E-09
Rh 45. 103. 103.000000 1.259E+01 9.510E-10
Pd 46. 106. 106.000000 5.012E+01 3.896E-09
Ag 47. 108. 108.000000 1.738E+01 1.376E-09
Cd 48. 112. 112.000000 5.754E+01 4.727E-09
In 49. 115. 115.000000 6.607E+00 5.572E-10
Sn 50. 119. 119.000000 1.380E+02 1.205E-08
Sb 51. 122. 122.000000 1.072E+01 9.587E-10
Te 52. 128. 128.000000 1.738E+02 1.631E-08
I 53. 127. 127.000000 3.236E+01 3.014E-09
Xe 54. 131. 131.000000 1.479E+02 1.421E-08
Cs 55. 133. 133.000000 1.349E+01 1.316E-09
Ba 56. 137. 137.000000 1.660E+02 1.667E-08
La 57. 139. 139.000000 1.660E+01 1.692E-09
Ce 58. 140. 140.000000 4.266E+01 4.380E-09
Pr 59. 141. 141.000000 6.310E+00 6.525E-10
Nd 60. 144. 144.000000 3.090E+01 3.264E-09
Pm 61. 147. 147.000000 1.000E-30 1.078E-40
Sm 62. 150. 150.000000 9.550E+00 1.051E-09
Eu 63. 152. 152.000000 3.548E+00 3.955E-10
Gd 64. 158. 158.000000 1.230E+01 1.426E-09
Tb 65. 159. 159.000000 2.239E+00 2.611E-10
Dy 66. 163. 163.000000 1.479E+01 1.768E-09
Ho 67. 165. 165.000000 3.236E+00 3.916E-10
Er 68. 167. 167.000000 9.333E+00 1.143E-09
Tm 69. 169. 169.000000 1.413E+00 1.751E-10
Yb 70. 173. 173.000000 9.120E+00 1.157E-09
Lu 71. 175. 175.000000 1.349E+00 1.731E-10
Hf 72. 179. 179.000000 5.623E+00 7.382E-10
Ta 73. 181. 181.000000 7.413E-01 9.840E-11
W 74. 184. 184.000000 4.898E+00 6.609E-10
Re 75. 186. 186.000000 1.905E+00 2.599E-10
Os 76. 190. 190.000000 2.455E+01 3.420E-09
Ir 77. 192. 192.000000 2.344E+01 3.301E-09
Pt 78. 195. 195.000000 4.898E+01 7.004E-09
Au 79. 197. 197.000000 7.079E+00 1.023E-09
Hg 80. 201. 201.000000 1.349E+01 1.989E-09
Tl 81. 204. 204.000000 6.761E+00 1.011E-09
Pb 82. 207. 207.000000 1.148E+02 1.743E-08
Bi 83. 209. 209.000000 5.129E+00 7.861E-10
Po 84. 209. 209.000000 1.000E-30 1.533E-40
At 85. 210. 210.000000 1.000E-30 1.540E-40
Rn 86. 222. 222.000000 1.000E-30 1.628E-40
Fr 87. 223. 223.000000 1.000E-30 1.635E-40
Ra 88. 226. 226.000000 1.000E-30 1.657E-40
Ac 89. 227. 227.000000 1.000E-30 1.665E-40
Th 90. 232. 232.040000 1.230E+00 2.093E-10
Pa 91. 231. 231.040000 1.000E-30 1.694E-40
U 92. 238. 238.030000 3.162E-01 5.520E-11