6. We can use the number of protons of the atom in order to identify the atom, since there is a direct correlation between number of protons, electrons and atomic number, in a neutral atom, all 3 values are equal, therefore, 17 protons it is Chlorine
7. In old times it was thought that the atom was the smallest unit of everything, but now we know that atoms are made of subatomic particles, the most common ones are: protons, electrons and neutrons. These particles have a few differences, one of these differences is their charge, for electrons we will have a negative charge, or -1, for protons, a positive charge, or +1, and for neutrons they are neutral particles, charge 0. Therefore the answer will be letter C electron = -1 and neutron = 0