We have some protons and neutrons and want to create a nucleus.
We must do work against the Coloumb force to bring these protons and neutrons together to form the nucleus, this increases the energy of the system. Hence the energy (or mass) of the nucleus should be greater than the energy (or mass) of the constituent parts. this is not correct though and I’m not sure why
Likewise, when we want to disassemble the nucleus, this energy should be released.
However, this is not the case, because energy is required to split a nucleus.
So why is my logic incorrect?