//---------------------------------------------------------- air 3 14.01 16. 39.95 7. 8. 18. 1.205e-3 .755 .231 .014 0 1 30. .001 0 silicon 1 28.0855 14.0 2.33 1 1 20. .001 0 iron 1 55.847 26. 7.87 1 1 20. .001 0