Electromagnetic radiation<span>, is a form of energy emitted by moving charged particles. As it travels through space it behaves like a </span>wave<span>, and has an oscillating electric field component and an oscillating magnetic field. These </span>waves<span> oscillate perpendicularly to and in phase with one another.</span>
The source of electromagnetic waves are charged particles that begin to oscillate when acted upon by a disturbance. These oscillating particles create an oscillating magnetic field. The oscillating magnetic field then creates an oscillating electric field, and an oscillating electric field in turn creates an oscillating magnetic field.
the newspaper one is a chemical change because the chemicals in the paper have reacted with something and turned a different color. the wax one is a physical change because it is a change in the phase of matter, which is always a physical change (still the same substance chemically)