Electromagnetic Spectrum PDF

 ELECTROMAGNETIC SPECTRUM OBJECTIVES: > Explain how an electromagnetic wave is produced. > Compare the relative wavelengths of the different types of electromagnetic waves. > Cite uses of electromagnetic waves. > Enumerate and explain the effects of EM waves on humans and environmen...

 ELECTROMAGNETIC SPECTRUM OBJECTIVES: > Explain how an electromagnetic wave is produced. > Compare the relative wavelengths of the different types of electromagnetic waves. > Cite uses of electromagnetic waves. > Enumerate and explain the effects of EM waves on humans and environment VALUES: > Show care and concern for one’s health and the environment. > Exercise caution when dealing with electromagnetic waves. > Promote the use of wireless technology. LINK 1: https://www.youtube.com/watch?v=m4t7gTmBK3g ELECTROMAGNETIC (EM) SPECTRUM - continuous range of electromagnetic waves arranged in order of frequency or wavelength - divided into regions on the basis of a certain frequency or wavelength interval  RADIO WAVE  ULTRAVIOLET  MICROWAVE  X – RAYS  INFRARED  GAMMA RAYS  VISIBLE LIGHT ELECTROMAGNETIC (EM) WAVES - also called electromagnetic radiations - are transverse waves produced by accelerating charges which travel in a vacuum and in a material medium 8 - have a common speed of 3 x 10 m/s in a vacuum - can be ionizing (such as x – rays and gamma rays) or non - ionizing   Ionizing radiation has sufficient energy to produce ions in matter at the molecular level. If that matter is a human significant damage can result including damage to DNA and denaturation of proteins  Ionizing radiation has many beneficial applications, including uses in medicine, industry, agriculture and research.  Non - ionizing radiation includes the other parts of the electromagnetic spectrum. Although considered less dangerous than ionizing type, it still poses some health issues TAKE NOTE:  The longer the wavelength, the lower the energy and frequency.  The shorter the wavelength, the higher the energy and frequency. ELECTROMAGNETIC (EM) SPECTRUM  HOW DO ELECTROMAGNETIC WAVES AFFECT US? LINK 2: https://www.youtube.com/watch?v=cfXzwh3KadE ELECTROMAGNETIC SPECTRUM  RADIO WAVE  ULTRAVIOLET  MICROWAVE  X – RAYS  INFRARED  GAMMA RAYS  VISIBLE LIGHT RADIO WAVES - the longest of all electromagnetic waves - its frequency ranges from 30 kHz to 3000 MHz - discovered by Heinrich Hertz in 1887 - produced by an alternating current (AC) circuit attached to an antenna - used to generate and pick up signals at certain frequency  The sun and the planet Jupiter are extraterrestrial sources of radio waves. RADAR (RADIO DETECTION AND RANGING)  makes use of radio waves o detection of objects o air traffic control o weather forecasting o tracking satellites & o military surveillance debris OTHER APPLICATION OF RADIO WAVES:  Automatic doors  WiFi (Wireless Fidelity)  GPS (Global Positioning System)  RFID (Radio Frequency Identification)  EC tag (paying toll in expressways)  e - Passport  UPC (Universal Product Code) or Bar code MEDICAL APPLICATIONS OF RADIO WAVES  MRI (Magnetic Resonance imaging) allows viewing the internal parts of the human body without invasive exploratory surgery  Ideal for reducing the cellulite on the body, wrinkles and fine lines on the face and for tightening sagging or loose skin LINK3 ON RADIOWAVE: https://www.youtube.com/watch?v=OzDmEA8x0nQ MICROWAVES - discovered by James Clerk Maxwell in 1864 - its frequency ranges from 300 MHz to 300 GHz -3 - wavelength corresponding to 10 m to -1 10 m - are considered as high – frequency radio waves and are mainly used for communication, especially from 2 GHz to 40 GHz  APPLICATIONS OF MICROWAVES  used for long – distance telephone calls  used to send signals for cable television as well as video or audio feeds from production vans to broadcast stations  used in remote sensing for disaster management and mapping  used in weather forecasting (Microwave Doppler radars)  used to cook food (microwave oven)  used in industrial processes for drying and curing products MEDICAL APPLICATIONS OF MICROWAVES microwave ablation uses the heat of the microwaves to shrink or destroy tumors Microwave imaging used to monitor the progress of treatment in breast cancer that can be distinguished as benign or malignant through microwave tomography LINK 4 ON MICROWAVE: https://www.youtube.com/watch?v=UZeBzTI5Omk  INFRARED WAVES - literally means “below red” - discovered by Sir William Herschel in 1800 - have a lower frequency than the red part of the visible light 11 - frequencies range from 3 x 10 Hz to 14 4 x 10 Hz with wavelengths ranging from -7 -3 7.5 x 10 m to 10 m  We do not see infrared radiation but we feel it as heat.  Higher temperature produces shorter infrared rays.  APPLICATIONS OF INFRARED WAVES  used in remote controls for television sets  burglar alarm system  night vision cameras  certain types of thermometers  Foods can be cooked using infrared radiation.  Computers, laptops, palmtops and printers are equipped with infrared data association ports that enable us to transfer and print data without connecting with cable. devices using IR must have a clear line of sight between them MEDICAL APPLICATIONS OF INFRARED WAVES  Medical infrared imaging used for diagnosis and prognosis o oncology o sports medicine o rheumatology o orthopedics  Physiotherapists use heat lamps to heal sports injuries. LINK 5 ON INFRARED: https://www.youtube.com/watch?v=i8caGm9Fmh0 VISIBLE LIGHT - electromagnetic radiations in the range 14 14 of 4 x 10 Hz to 8 x 10 Hz with -7 corresponding -7 wavelengths of 4 x 10 m to 8 x 10 m R RED O ORANGE Y YELLOW G GREEN B BLUE I INDIGO V VIOLET  APPLICATIONS OF VISIBLE LIGHT  allows us to see objects  used in traffic lights, commercial displays, car headlights and trail lights.  used by plants in photosynthesis  Visible light communication (VLC) used for simultaneous audio and video streaming  LASER (Light Amplification by Stimulated Emission of Radiation) MEDICAL APPLICATIONS OF VISIBLE LIGHT  LASER (Light Amplification by Stimulated Emission of Radiation) o optical imaging o treatment o surgery o biomedical research o endoscopy o microscopy LINK 6 ON VISIBLE LIGHT: https://www.youtube.com/watch?v=PMtC34pzKGc  ULTRAVIOLET (UV) RADIATION - discovered by a German physicist Johann Wilhelm Ritter 14 17 - frequencies ranging from 8 x 10 Hz to 10 Hz with -10 -7 wavelengths ranging from 6 x 10 m to 4 x 10 m KINDS OF UV:  UV A with wavelength range of 315nm to 400 nm - accounts for 95% of solar UV reaching the Earth  UV B with wavelength of 280 nm to 314 nm - filtered by the ozone in the atmosphere  UV C with wavelength of 279 nm to 60 nm - almost completely absorbed by the atmosphere and does not reach earth’s surface APPLICATIONS OF ULTRAVIOLET RADIATION  black lights  used to detect forged bank notes  used during forensic investigations at crime scenes, in searching for traces of blood and other body fluids, fingerprints, and footprints  used to sterilize medical equipment and purify water  used in pest – control devices and fly traps  used in theatres to produce the “glow in the dark” effect  MEDICAL APPLICATIONS OF ULTRAVIOLET  UV A  used to treat skin condition like psoriasis and vitiligo that cause depigmentation of parts of the skin  UV stimulates the production of vitamin D in our body LINK 7 ON UV: https://www.youtube.com/watch?v=QW5zeVy8aE0  X - RAYS - also called Roentgen rays - discovered by German physicist Wilhelm Conrad Roentgen -12 -8 - wavelengths ranging from 10 m to 10 m - produced by the sun and other stars, and produced when accelerated electrons hit a metal and some medical equipment  The letter X is normally used to represent an unknown quantity and called such because he did not know their nature or origin. CLASSIFICATION:  Soft X – rays can penetrate soft substances like flesh and bones.  Hard X – rays which are more penetrating than soft and are used mainly in industries.  APPLICATIONS OF X RAYS  used to detect abnormalities in the skeletal system like fractures and tumors  used dental imaging  CAT (Computer Axial Tomography) - taking photographs of internal body parts  used in airport security checks to see the inside of passenger luggage  used to study the arrangement of atoms in a crystal by a process called diffraction LINK 8 ON XRAY: https://www.youtube.com/watch?v=CCAYcuCWOnM GAMMA RAYS - are given off by radioactive materials like cobalt – 60 and cesium - 137 - discovered in 1900 by a French chemist and physicist Paul Villard - are highly penetrating because of their very short -14 wavelengths, ranging from less than 10 m -10 to 10 m SOURCES:  sun  clouds of interstellar matter  remnants of supernovae  APPLICATIONS OF GAMMA RAYS  used in industries to detect cracks in metal  used to sterilize equipment and commercial products  non – contact industrial sensors  refining  chemical  soaps  mining  food  detergents  pulp and paper industries to control volume levels, density and thickness  Food irradiation to kill bacteria insects and parasites that can cause foodborne diseases  APPLICATIONS OF GAMMA RAYS  used in agriculture (gamma radiation) to help breed new seed varieties with higher yields  used to eradicate pests like fruit flies  radiotherapy  destroy cancer cells  can be external or internal  In external radiotherapy, patient is exposed to a beam of radiation. Examples include: gamma knife surgery and stereotactic radiotherapy.  In internal radiotherapy, radiation comes from implants or liquids placed inside the body (brachytheraphy) LINK 9 ON GAMMA: https://www.youtube.com/watch?v=TA5SLDiIUWs