An example of an atom that has no charge is one that

an atom with no charge has 2 protons, 2 electrons, and 1 neutron.

explanation:

protons have a positive charge, electrons have a negative charge, and neutrons have no charge. as the proton is a positively charged particle and the electron is negatively charged, so the number of electrons should be equal to the number of protons so that the net charge on an atom is zero.

it's c. elements are placed in rows based on how may valencies electrons have.