, which has a mass of 9.012 182 24 amu. The mass of a proton is 1.007 276 47 amu and the mass of a neutron is 1.008 664 90. One amu = 1.6605 
10–27 kg and the speed of light is 3.00 
Add the masses of the the 4 protons and 5 neutrons in Be-9 (Really the 9 electrons should be included with that many sig figs, but it wasn't given in the problem. If you want to use it, it is 5.486 x 10-4 amu per electron)
Take the difference between the sum of the subatomic particle masses and the actual weight of Be-9 in amu.
Convert to kg by multiplying by 1.6605 x 10-27 kg/amu (That is the mass defect)
Plug the mass defect into the equation E = Δmc2 where c = 3.00 x 108 m/s and Δm is the mass defect.
The binding energy per nucleon will be E/9 in J/nucleon
