1. The problem statement, all variables and given/known data Using the Uncertainty Principle show arithmetically that neutrons can't be formed by a proton and an electron. 2. Relevant equations 3. The attempt at a solution I can see that if neutrons were made out of a proton and an electron they would just attract each until they were together, and after that their momentums would be 0 and we could also know their position, by I don't know how to show it arithmetically.