Which of the following is false regarding the structure of atoms? A. Most of the mass is in the nucleus. B. Atoms are naturally electrically neutral. C. The nucleus is a very small region of the atom. D. Losing a proton affects only an atom's mass and charge.Which of the following is false regarding the structure of atoms? A. Most of the mass is in the nucleus. B. Atoms are naturally electrically neutral. C. The nucleus is a very small region of the atom. D. Losing a proton affects only an atom's mass and charge.