27. Which of the following best describes the properties of protons, neutrons, and electrons
A. Protons and neutrons have the same mass; the mass of an electron is very close to zero
B. Protons and electrons have the same mass; the mass of a neutron is double the mass of a proton
C. Protons, neutrons, and electrons all have the same mass.
D. Neutrons and protons have the same mass; the mass of an electron is half the mass of a proton