There's growing evidence ...Fentanyl (or hydromorphone) have a better side effect profile than morphine (remember the vaunted vasodilation is only a side effect) thereby making fentanyl a better choice..
The subatomic particles in the nucleus of a carbon atom are protons and neutrons. The atomic nucleus contains protons and usually neutrons (except for hydrogen-1 (protium) atoms. The number of protons is an element's atomic number and is the same for all atoms of an element. Carbon has atomic number #6#. So all atoms of carbon have #6# protons in their atomic nuclei.
The exterior shell of the atom is not the only place electrons can be found in an atom. Though the electron shell is the only stable location for electrons, a heavy atom that undergoes beta decay can emit an electron from its nucleus. To avoid confusion, electrons emitted by the nucleus are referred to as beta particles. Learn more about Atoms & Molecules