AP Chemistry A. Allan Chapter 7 Notes - Atomic Structure and Periodicity 7.1 Electromagnetic Radiation A. Types of EM Radiation (wavelengths in meters) 10-12 10-10 10-8 4 to 7x10-7 10-4 10-2 1 102 104 Wavelength increases Frequency decreases Energy decreases Speed is constant = 2.9979 x 108 m/sec B. Properties of EM Waves 1. Wavelength (l) a. Distance between two consecutive peaks or troughs in a wave b. Measured in meters (SI system) 2. Frequency (n) a. Number of waves that pass a given point per second b. Measured in hertz (sec-1) 3. Speed ( c ) a. Measured in meters/sec 4. Relationship of properties a. c=nl gamma xrays UV visible IR micro Radio waves FM short AM 7.2 The Nature of Matter