Hi, I have a couple of questions here I am having a little bit of difficulty with. 1) What is the wavelength of an X-ray that has a period of 1.30x10e-10s? 2) A certian EMR has a wavelength of 2.14x10e-5m in air. What is the wavelength is water(n = 1.33)? I am not looking for the answers as I prefer to be able to understand the questions and how the answers are correct but I have searched the the textbook on this unit about magnetic fields and electric fields but can not find anything of wavelengths and periods. If anyone could tell me the equation to use or anything it would be great All I know is that Speed of wave = Frequency * Wavelength Is the period the frequency? and the speed of wave would be the speed of light?