Q2. Draw again on a piece of paper your drawing from the plate with all its information. Next draw on each equipotential line a number of arrows (at least 4) depicting the Electric Field due to the pennies (that we take to be point charges of equal and opposite charge). For this task you need to identify which penny is positively charged and which negatively charged. Discuss with your group how you can identify which is which with only knowledge the sequence of the potential difference values of the equipotential line.

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -

Is there a picture to go along with this