1. The problem statement, all variables and given/known data Calculate the binding energy per nucleon for 4He. Mass is 4.0026u 2. Relevant equations E=Δmc^2 3. The attempt at a solution This is my plan of attack, first find the Δm. Mnucleon-Mnucleus [Are these terms right? Nucleon - Nucleus ?] Δm=4.0026u-(2p+2n)=-0.02928u E=Δmc^2 =-2.6352x10^15J/nucleus But the question asked for J/nucleon and I'm not sure what to do now. The correct answer is -1.13x10^-12J/nucleon.