oh my... thank you for your contribution verpies "intrinsic hyperfine magnetic field inside metallic iron"  that is a mouthful but with the numbers you have given i can calculate the magnetic field energy of one iron atom. Density of iron is 7.874 g/cm3 so 1cm³ of iron weighs 7.874g iron has 55.845 g/mol 7.874 / 55.845 = 0.140997 ~ 0,141 1 mole = 6.022x10^23 particles 6.022x10^23 x 0,141 = 8.49086x10^22 and now i divide 433.3 Joules by 8.49086x10^22 433.3 / 8.49086x10^22 = 5.10313x10^21 Joule 1 Joule [J] = 6.241506363094x10^18 Electronenvolt [eV] 5.10313x10^21 x 6.241506363094x10^18 = 0,0318512324 eV ...so the intrinsic hyperfine magnetic field energy of 1 iron atom is 0,0318512324 eV? that is grossly underwhelming
