| If a nucleus has too many protons for its number of neutrons, it will be radioactive. |
| Our planet is incessantly bombarded with a rain of cosmic rays, charged stable particles, such as protons and electrons. |
| Yet experiments indicated that quarks within protons were only loosely bound together. |
| Alpha emitting radionuclides emit alpha particles, each consisting of 2 protons and 2 neutrons. |
| The protons recombine with the oxygen in the air that's also flowing through the fuel cell and is then expelled as water vapor. |
| That process would briefly liberate the quarks and gluons that make up protons and neutrons. |
