Electromagnetic Spectrum - Lesson Notes PDF

ELECTROMAGNETIC SPECTRUM Quarter 2 Lesson 1 Lesson Objectives: At the end of the lesson, you should be able to: describe the forms of electromagnetic waves and their properties; describe how electromagnetic spectrum is arranged; identify uses for waves of electro...

ELECTROMAGNETIC SPECTRUM Quarter 2 Lesson 1 Lesson Objectives: At the end of the lesson, you should be able to: describe the forms of electromagnetic waves and their properties; describe how electromagnetic spectrum is arranged; identify uses for waves of electromagnetic spectrum.  WHAT IS AN ELECTROMAGNETIC WAVE? Electromagnetic waves are waves that are created as a result of vibrations between an electric field and a magnetic field. In other words, EM waves are composed of oscillating magnetic and electric fields. Magnetic Field Electric Field FREQUENCY Frequency (f) is the number of waves that pass a fixed point in a given amount of time. Frequencies of electromagnetic waves range from thousands of waves per second to trillions of waves per second. Unit of measurement: Hertz (Hz) Symbol: f WAVELENGTH Wavelength (λ) is the distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave. Unit of measurement: meters (m) Symbol: Lambda (λ) PHOTON ENERGY Photon Energy (E) is the amount of energy directly proportional to the photon's electromagnetic frequency and thus, equivalently, is inversely proportional to the wavelength. The higher the photon's frequency, the higher its energy. Unit of measurement: Electron Volts (eV) Symbol: E THE ELECTROMAGNETIC SPECTRUM  ELECTROMAGNETIC SPECTRUM Electromagnetic Spectrum is the entire distribution of electromagnetic radiation according to frequency or wavelength. ELECTROMAGNETIC SPECTRUM INCREASING WAVELENGTH (M) INCREASING FREQUENCY (Hz) INCREASING PHOTON ENERGY (EV)  RADIO WAVE Frequency: 3 KHz – 300 GHz Wavelength: 30 cm – thousands of meters Photon Energy: 1.2 × 10-11 eV Applications: AM & FM radio, television, mobile phones, magnetic resonance imaging, etc. Radio waves are the longest wavelength electromagnetic waves that are used for transmitting data from radio, satellites, and radar.  MICROWAVE Frequency: 1GHz – 1000 GHz Wavelength: 30 cm – 0.03 cm Photon Energy:1.2 × 10-4 eV Applications: Oven cooking, mobile phones, aircraft navigation, terrain mapping, molecular research, long distance communication, etc. Microwaves are a portion or "band" found at the higher frequency end of the radio spectrum, but they are commonly distinguished from radio waves because of the technologies used to access them.  INFRARED Frequency: 3 × 1013 Hz Wavelength: 10000 nm Photon Energy: 0.12 eV Applications: Heating and drying, night vision cameras, satellite remote sensing, remote controls, etc. Infrared is a region of the electromagnetic radiation spectrum that are longer than those of visible light, but shorter than those of radio waves. It causes the bonds between molecules to move, releasing energy that is felt as heat. VISIBLE LIGHT Frequency: 7.5 × 1014 Hz Wavelength: 400 - 700 nm Photon Energy: 1.8 – 3.1 eV Applications: What the typical eye and film can see, visible light photography, etc. Visible Light is the segment of the electromagnetic spectrum that the human eye can view. ULTRAVIOLET Frequency: 3 × 1015 Hz Wavelength: 100 nm Photon Energy: 1.2 keV Applications: Sterilization, curing inks and resins, phototherapy, dental applications, etc. Ultraviolet is a type of electromagnetic radiation that has shorter wavelengths than visible light. This means that UV light has a higher frequency than visible light.  X-RAY Frequency: 3 × 1017 Hz Wavelength: 1 nm Photon Energy: 120 keV Applications: Medical examination of bones, teeth, and vital organs; treatment for types of cancer; astrophysics, etc. X-rays are a form of electromagnetic radiation, similar to visible light. Unlike light, however, x-rays have higher energy and can pass through most objects, including the body. GAMMA Frequency: 3 × 1023 Hz Wavelength: 1 × 10-6 nm Photon Energy: 1.2 GeV Applications: Sterilize medical equipment; Sterilize food (irradiated food); Used as tracers in medicine; Radio Therapy- In oncology, to kill cancerous cells; Gamma-Ray Astronomy. Gamma refers to the part of the electromagnetic spectrum with the most energy and shortest wavelength. ELECTROMAGNETIC SPECTRUM INCREASING WAVELENGTH (M) INCREASING FREQUENCY (Hz) INCREASING PHOTON ENERGY (EV) Effects of electromagnetic radiation  Effects on Living Organisms Some type of EM wave carry enough energy to ionize atoms and dissociate molecules that can damage cells and DNA. Prolonged exposure to high-energy radiation has been associated to different types of cancer and birth defects. Ionizing Radiation: Ultraviolet, X-ray and Gamma Rays.  Effects on Environment Most radiation is absorbed by the environment such as the Ozone Layer. However, the gradual thinning of the ozone layer caused by human made pollutants contributes to the increase of UV rays reaching Earth, resulting in a rise of global temperature.  SUMMARY What are the different forms of Electromagnetic wave and their properties?  SUMMARY How is the electromagnetic spectrum arranged? INCREASING FREQUENCY (Hz) INCREASING PHOTON ENERGY (EV) INCREASING WAVELENGTH (M)  SUMMARY What are the practical applications of each type of EM wave? THANK YOU!