Suppose you have two magnets. magnet a doesn't have its poles labeled, but magnet b does have a clearly labeled north and south pole. if these two are brought into contact with one another, which of the following could you expect?

a. the side of magnet a that's repelled by magnet b's south pole must be magnet a's north pole.

b. the side of magnet a that's repelled by magnet b's north pole must be magnet a's south pole.

c. the side of magnet a that's attracted to magnet b's south pole must be magnet a's north pole.

d. the side of magnet a that's attracted to magnet b's north pole must be magnet a's north pole.

The opposite pole attracts each other and the similar pole repel each other. Which means only C is true.

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 -