Neutrons are known to be heavier than protons. This is because the neutron contains more mass. It has more energy too. They may seem like things that you should not know about but they can be essential. For instance, do you realize that if protons are heavier than neutrons, all of those that are unmatched would end up becoming protons?
This can be a problem because this means that not all protons can be saved. Neutron to proton mass has made the world more stable overall. A lot of experts do not want to think about how life could be if there are some differences. There are still a lot of scientists and researchers who would like to know more about this.