Which group on the periodic table is naturally stable (unreactive) due to the fact that the atoms' valence shells are full?

Time remaining 58: 10 an atom that has 84 protons and 86 neutrons undergoes a reaction. at the end of the reaction, it has 82 protons and 84 neutrons. what happened to the atom? it accepted radiation in a chemical reaction it donated neutrons to another atom in a chemical reaction it emitted an alpha particle in a nuclear reaction. it accepted protons in a nuclear reaction. mark this and retum save and exit next submit