Which statements accurately describe Earth’s magnetic field? Check all that apply. The magnetic field lines flow from Earth’s geographic South Pole to Earth’s geographic North Pole. The magnetic field is created by magnetic rocks on the surface. The magnetic poles line up exactly with Earth’s geographic poles. The magnetic field is generated in Earth’s core. The magnetic field is similar to the magnetic field of a bar magnet.

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 -

Lexy is correct because angle r is between the incident wave,  n  = 0, and a diffracted wave.