Name: Grade & Section:
Lesson 1
Practical Applications of the High Frequency
Regions of Electromagnetic Waves
MELC: Cite examples of practical applications of the different regions of EM waves, such as
the use of radiowaves in telecommunications (S10FE-IIc-d-48)
Objectives: 1. Identify the different high frequency regions of EM Waves
2. Determine practical applications of Ultraviolet Radiation, X-ray, and Gamma rays
3. Recognize the importance of high frequency regions of EM waves
Let’s Explore and Discover
Technology has been a great contributor of developments
Unlocking Difficulties specifically in terms of communication. Formerly, we were using
o UV light got its wired telephones, but as time went by, the wireless technology
name because the has been introduced to us – radio and television, cellular
spectrum consists phones, WIFI, Bluetooth, e-mails and other wireless media for
of electromagnetic communication, in which some are products of electromagnetic
waves with (EM) spectrum travelling through space.
frequencies higher
than those that As a review, Electromagnetic (EM) spectrum is generally
humans identify as divided into seven regions, in order of decreasing wavelength
the color violet. and increasing energy and frequency. The common designations
(Source:“The are: radio waves, microwaves, infrared (IR), visible light,
Electromagnetic ultraviolet (UV), X-rays, and gamma rays. Typically, lower-
Spectrum,” Lumen energy radiations, such as radio waves, is expressed as
Boundless Physics, frequency; microwaves, infrared, visible and UV light are usually
accessed November 26, expressed as wavelength; and higher-energy radiations, such as
2020, X-rays and gamma rays, are expressed in terms of energy per
https://courses.lumenle photon.
arning.com/boundless-
physics/chapter/the- (Source: “What is Electromagnetic Radiation?” Live Science, last
electromagnetic- modified March 13, 2015, https://www.livescience.com/38169-
spectrum/.) electromagnetism.html.)
High Frequency region of
electromagnetic waves includes
Ultraviolet radiation, X-ray, and
Gamma Rays.
A. Ultraviolet
Radiation is a portion of the
EM spectrum extending from
the violet, or short- (Image Source: VectorMine, Electromagnetic Spectrum, Free
wavelength, end of the visible Royalty, https://depositphotos.com/181201252/stock-
light range, to the X-ray illustration-electromagnetic-spectrum-infographic-
diagram.html.)
region. It is undetectable by
the human eye. Although, when it falls on certain materials, it may cause them to
fluoresce - emit electromagnetic radiation of lower energy, such as visible light.
(Source: “Ultraviolet Radiation,” Britannica, accessed November 26, 2020,
https://www.britannica.com/science/ultraviolet-radiation.)
1
Practical applications of Ultraviolet Radiation includes production of Vitamin D
in our skin, sterilization and disinfection, treatment to illnesses, photography, forensic and
investigative science.
APPLICATIONS OF ULTRAVIOLET RADIATION
UV exposure stimulates vitamin D UV photography, which is often
production in the body. In medical used for medical, scientific and
practice, one example is UV lamps forensic purposes, uses specific
can be used for treating psoriasis (a lenses to let UV light pass
condition causing itchy, scaly, red through the camera's lenses.
patches on the skin). Exposure to UV Nature photographers may use
light is a known risk for skin cancer, UV photography to capture
some cancerous skin conditions can patterns in flowers the human
be treated using UV light. eye cannot see.
*Fake currency notes, security Used to analyze the chemical
papers, passports, certificates, and structure of a compound via
other specialized documents will give color changes, UV is often used
different fluorescent due to the in chemical and biological
difference in sizing and the fibers plants, hospitals, water quality
present in the documents, specific
control laboratories, and the food
watermarks (Chemical and Mechanical)
can be easily differentiated based on industry. It can screen unwanted
their luminescence under UV rays. compounds during the
production of drinking water.
(Sources: 1. “What are the uses of Ultraviolet Light?” Sciencing, last modified April 26, 2018,
https://sciencing.com/homemade-uv-sterilizer-5852021.html.
*2. “Application of Ultra Violet (UV) Radiations in Questioned Document
Examination,” Forensic science Expert, last modified December 12, 2019,
https://www.forensicscienceexpert.com/2019/12/application-of-ultra-violet-
uv.html#:~:text=Ultraviolet%20(UV)%20illumination%20techniques%20are,on%20clo
thes%2C%20detecting%20ink%20stains.)
B. X- rays are electromagnetic waves like radio and
light waves. These all travel at the speed of light,
which is 300 000 km per second.
Unlocking of A common application is
Difficulties in the form of X-ray
machines, which take photos
o Photon is the
smallest discrete of a patient’s body in cases of
amount or quantum broken arms or legs. The (Image Source: Media
Production,Airport security
of electromagnetic rays go through the skin and
radiation. It is the check,Free Royalty,
flesh easily, showing up as https://www.gettyimages.com/det
basic unit of all dark areas on the film, but
light. ail/photo/airport-security-check-
with more difficulty through royalty-free-image/527890060.)
bone. They are slowed down
(Source: “What exactly and so these areas are much lighter. X-rays can also be used to
is a photon?” ZME
Science, last modified kill cancer cells, but also kill healthy ones, so must be used with
June 23, 2017, much care.
https://www.zmescienc X-ray photons carry enough energy to ionize atoms, a very
e.com/science/what-is- high radiation dose over a short amount of time causes radiation
photon-definition- sickness, while lower doses can give an increased risk of
04322/.)
radiation-induced cancer.
Other practical uses of X-rays are in industry, at airports to check
customers and baggage, and by art historians to see if a picture has been
painted on top of an older one.
2
C. Gamma radiation, also known as gamma rays or
Unlocking of hyphenated as gamma-rays and denoted as γ, is
Difficulties electromagnetic radiation of high frequency and therefore
o Though Cosmic rays high energy. Gamma rays and neutrons are more
are some form of penetrating, causing diffuse damage throughout the body
electromagnetic (radiation sickness, cell’s DNA damage, cell death due to
radiation, they are damaged DNA, increasing incidence of cancer) rather than
actually subatomic burns. High frequency waves like the gamma rays are
particles travelling at harmful because they carry very high amount of energy that
significant fractions of
enables them to penetrate and kill living cells.
the speed of light.
Primarily atomic
nuclei (hydrogen and (Source: “The Electromagnetic Spectrum,” Lumen Boundless
helium nuclei) are the Physics, accessed November 26, 2020,
most common, but https://courses.lumenlearning.com/boundless-
nuclei of all naturally physics/chapter/the-electromagnetic-spectrum/.)
occurring elements
have been detected.
(Source: “Cosmic Rays,”
Centre for Astrophysics
and Supercomputing
HOW ARE GAMMA
(COSMOS), accessed
November 26,2020.
RAYS USED?
https://astronomy.swinb
urne.edu.au/cosmos/C/
Cosmic+Rays.)
MEDICINE
Radiation therapy uses high-energy
gamma rays to kill cancer cells and shrink
tumors. Gamma Knife Radiosurgery is a
ONE special form of radiotherapy. It uses
beams of gamma rays to treat injured
brain tissue by damaging the DNA of
dangerous cells.
FOOD INDUSTRY
Food producers can use gamma sterilization. That’s a
type of irradiation that uses gamma rays to increase the
shelf-life of food and drinks. Food products are
bombarded with a source of high-energy gamma rays,
TWO normally Cobalt-60 or Cesium-137. These gamma rays
modify chemical bonds and kill bacteria that can cause
illness. This is an important process for food
preservation, just like canning fruit or pasteurizing
dairy products.
INDUSTRIAL
Industrial radiography is a method used to test materials for
flaws, such as cracks. In industrial radiography, gamma rays let
people look for problems without damaging the materials.
THREE Industrial radiography is a nondestructive way to test products
such as pipes, welded materials or airplane parts. These
testing procedures ensure that the materials are safe and of good
quality. X-rays and ultrasound radiation are also used for this
work.
(Source: “Gamma Rays: Helper or Hazard?”Lets talk Science, last modified
November 23, 2019, https://letstalkscience.ca/educational-resources/stem-in-
context/gamma-rays-helper-or-hazard.)
