How to remember the EM spectrum and relevant equations

[theonlytycrane]

I found it most helpful to go with a condensed graphic like above. I put relevant equations together and put this on my 10 min tutorial scratch paper for quick reference.

The visible spectrum is within the 400 n.m. to 700 n.m. range and the arrows indicate which way wavelength and frequency increase. The "ROYGBIV" is to estimate which color area the wavelength is around and is helpful if a question asks about a specific shift. Complementary colors are easy with this too because they are always "two colors" away from one another. For example, the complementary color for red is green.

The non-visible regions are also listed in relation to one another and a quick note that light refraction (bending) increases with frequency is added. Hope this helps!

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[Horse Apiece]

What worked for me beyond brute memorization was that 700nm to 400nm with ROYGBIV, where red is highest at 700nm, violet/blue is lowest at 400nm. Then ultraviolet would just have a shorter wavelength than violet, and infrared would have a larger wavelength than red.

Shorter wavelength = Higher frequency from... (c[a constant speed] = (wavelength)(frequency)) so if wavelength goes up, frequency goes down.
Then harmful waves have higher frequency and low wavelength, so gamma and x-ray fall under this category.
While micro and radio waves have longer wavelengths and lower frequency.