Give three examples of action-reaction pairs

It will take annabelle 4 hours to complete her homework. if it took her 3 hours to finish 75%, then it probably took her 1 hour for every 25% she finished. if she finished 75%, she has 25% left to be done or 100% complete. 25% = 1 hour. so 3 hours + 1 hour = 4 hours or 100% complete

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 -