The primary colors are blue, red, and yellow.
The alkaline earth metals (the second group) because their ion charge is +2
Protons: <span>The mass of the proton is about 1,840 times the mass of the electron and slightly less than the mass of the neutron.
Electrons: </span><span>Electrons are arranged around the nucleus of atoms in regions called electron clouds or electron orbits.
Neutrons: </span><span>A neutron is one of two particles found inside the nucleus (central part) of an atom. The other particle is called a proton. Electrons are particles that move around an atom outside the nucleus.</span>
Elements with complete electron shells are most likely noble gases which have 8 valence electrons in their outer shell. So the letter farthest to the right should be the correct answer. Noble gases are found in group 18
