CHEMISTRY COMMUNITY

Do we need to know the different wavelengths/frequencies for light, uv light, radio waves, etc. or will we be given the wavelengths and frequencies for different things.

I would assume so, since some of the homework problems include those types of questions. Just remember that visible light is between 400 to 700 nm, infrared is between 700 to 1000 nm, UV is 10 to 400 nm, and gamma rays are anything smaller than that. You could memorize the frequencies if you'd like, but you can always convert the frequencies back into wavelengths in the end.

I would say that you don't need to memorize the all of different wavelengths, but I would know the order of the different wavelengths and have a general idea of the range of wavelengths for each type if light.

I believe it's important to know that visible light is in the range between 400-700 nanometers. I would also know that higher energy waves (gamma ray/x-ray/ultraviolet) have shorter wavelengths and higher frequencies. While lower energy waves (radio/microwave/infared) have longer wavelengths and lower frequencies. However, more information and building a solid foundation is never a bad thing.

I feel that it is essential to remember the order of the electromagnetic spectrum to be safe. One trick I use to memorize the order is coming up with an acronym. A common one is "Real Monkeys Insist Very Useful X-mas Gifts" (Radio, Microwaves, Infrared, Visible, Ultraviolet, X-rays, Gammas) This is in the order of decreasing wavelength and increasing frequency.

Remembering this helps me memorize the ranges. Like the comments above, I think it wouldn't hurt to memorize these: 100-400 nm (UV light), 400-700 nm (Visible Light), and 700nm- 1mm (Infrared).

Hope this helped!

In class, Dr. Lavelle never really stresses the need to memorize the different wavelengths and frequencies, but I would agree that memorizing that 400-700 nm is visible light and the order of different types of wavelengths would be extremely helpful. I think it is much more important to stress the key concepts of the chapter such as a longer wavelength means a lower frequency and therefore a lower energy of the photon.