1)if a boron atom has 5 protons, 6 neutrons, and 5 electrons, it has a mass of a)11 b)10 c)6 2)the atomic number of an atom is the total number of in the nucleus. a)protons and electrons b)protons c)neutrons 3)a lithium atom has 3 protons, 3 neutrons, and 3 electrons. which of the following sets of particles represents and isotope of this atom? a)4 protons, 3 neutrons, and 4 electrons b)3 protons, 4 neutrons, and 3 electrons c)4 protons, 4 neutrons, and 4 electrons