Consider the situation when almost all of the magnetic moments of a sample of a particular ferromagnetic metal are aligned. In this case, the magnetic field can be calculated as the permeability constant multiplied by the magnetic moment per unit volume. In a sample of iron, for example, where the number density of atoms is approximately 8.50 x 1028 atoms/m, the magnetic field can reach 1.96 T. If each electron contributes a magnetic moment of 9.27 x 10-24 A + m (1 Bohr magneton), how many electrons per atom contribute to the saturated field of iron? electrons/atom