Composition of BONE, CORTICAL (ICRP): Density (g/cm3) = 1.85000E+00 Mean Excitation Energy (eV) = 106.400000 COMPOSITION: Z = Atomic number WT = Fraction by weight Z WT 1 0.047234 6 0.144330 7 0.041990 8 0.446096 12 0.002200 15 0.104970 16 0.003150 20 0.209930 30 0.000100