Re: If I added neutrons to an object would it change the weight?

The short answer to your question is that you can't change gravity. It's one 
of the fundamental constants of the universe (As far as we can tell). 
However, you can change the *mass* of a nucleus by bombarding it with 
neutrons. This is done every day in experiments done at cyclotrons by 
nuclear physicists. They do this to search for new nuclei and to study the 
properties of known nuclei. This is also done at medical facilities to 
produce radio-isotopes for use in diagnoses.