Answer the following questions about the structure of the electromagnetic spectrum.
(a) List the seven principal regions of the electromagnetic spectrum in order of decreasing wavelength.
(b) For each region, state an approximate numerical range for wavelength (either as powers of ten in meters or using metric prefixes) sufficient to distinguish that region from its neighbors.
(c) A spectral line from an excited atom has a measured frequency of 7.5×1014Hz. Identify the region of the spectrum in which this line lies and justify your answer by referencing the ranges you provided in part (b).