When a bar magnet is broken into two pieces each piece has a north and south pole because

a
the magnetic fields reversed

b
every magnet is made of many aligned smaller magnets

с
bar magnets are permanent magnets

d
the magnetic poles have been isolated

Write maxwell's equations and discuss the terms involved and the results of each equation in classical electrodynamics. if it is possible to write these equations in integral form, give the integral forms. find the wave equation for electromagnetic waves from the maxwell equations. what is the propagation velocity of electromagnetic waves in space according to the wave equation you find?

Asun-sized star will spend most of its lifetime as a: white dwarf red giant protostar main-sequence star

Iron reacts with sulfur to form iron sulfide. if 60 grams of iron reacts with sulfur to produce 90 grams of iron sulfide, how much sulfur has been used in the chemical reaction?