The document discusses light as an electromagnetic wave, describing its characteristics including color which results from the visible wavelengths of light, and intensity which is measured based on brightness. It also provides background on theories of light throughout history and how Maxwell's electromagnetic theory established light as an electromagnetic wave exhibiting properties of wavelength, frequency, and speed.

1. Science
Quarter 3 – Module 4:
Color and Intensity of Light in
Terms of Its Wave
Characteristics
7

2. Science – Grade 7
Alternative Delivery Mode
Quarter 3 – Module 4: Color and Intensity of Light in Terms of Its Wave Characteristics
First Edition, 2020
Republic Act 8293, section 176 states that: No copyright shall subsist in any work of
the Government of the Philippines. However, prior approval of the government agency or office
wherein the work is created shall be necessary for exploitation of such work for profit. Such
agency or office may, among other things, impose as a condition the payment of royalties.
Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names,
trademarks, etc.) included in this module are owned by their respective copyright holders.
Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.
Published by the Department of Education
Secretary: Leonor Magtolis Briones
Undersecretary: Diosdado M. San Antonio
Printed in the Philippines by ________________________
Department of Education – Region III
Office Address: Matalino St., Diosdado Macapagal Center
Maimpis, City of san Fernando (P)
Telefax: (045) 598-8580 to 89
E-mail Address: region3@deped.gov.ph
Development Team of the Module
Writers: Arlene G. Quitos
Editors: Felerma G. Urbano
Reviewer: Shekinah Abigail G. Corpuz
Illustrator: Jinky H. Martin
Layout Artist: James Patrick S. Barias
Management Team: May B. Eclar, CESO III
Librada M. Rubio, PhD
Ma. Editha R. Caparas, EdD
Nestor R. Nuesca, EdD
Larry B. Espiritu, PhD
Rodolfo A. Dizon, PhD
Mary Queen P. Orpilla, PhD

3. 7
Science
Quarter 3 – Module 4:
Color and Intensity of Light in
Terms of Its Wave
Characteristics

4. Introductory Message
This Self-Learning Module (SLM) is prepared so that you, our dear learners, can
continue your studies and learn while at home. Activities, questions, directions,
exercises, and discussions are carefully stated for you to understand each lesson.
Each SLM is composed of different parts. Each part shall guide you step-by-step as
you discover and understand the lesson prepared for you.
Pre-tests are provided to measure your prior knowledge on lessons in each SLM. This
will tell you if you need to proceed on completing this module or if you need to ask
your facilitator or your teacher’s assistance for better understanding of the lesson.
At the end of each module, you need to answer the post-test to self-check your
learning. Answer keys are provided for each activity and test. We trust you that you
will be honest in using these.
In addition to the material in the main text, Notes to the Teacher are also provided
to our facilitators and parents for strategies and reminders on how they can best
help you on your home-based learning.
Please use this module with care. Do not put unnecessary marks on any part of this
SLM. Use a separate sheet of paper in answering the exercises and tests. And read
the instructions carefully before performing each task.
If you have any questions in using this SLM or any difficulty in answering the tasks
in this module, do not hesitate to consult your teacher or facilitator.
Thank you.

5. 1
What I Need to Know
This module discusses the nature and characteristics of light. It delves
particularly about the colors of light and intensity of light focusing only on its
characteristics as a wave.
At the end of this module, you are expected to:
1. Explain color and intensity of light in terms of its wave characteristics.
2. Create a color spectrum wheel to understand the relationship of frequency,
wavelength and energy; and
3. Cite applications on the importance of light in everyday living.
What I Know
Directions. Choose the letter of the correct answer and write it in your notebook/
on a separate sheet of paper.
1. ROYGBIV is the basic component of white light, which color of light has the
highest energy?
a. blue
b. green
c. orange
d. red
2. Which of the following is not true about the nature of light?
a. Light has a constant speed of 3 x 108 m/s in any medium.
b. Light is a form of energy that travels in space.
c. Light is a mixture of ROYGBIV colors of light.
d. Light is an electromagnetic wave.
3. What will be the comparison between red light and violet light, in a vacuum?
a. both have the same frequency
b. both have the same wavelength
c. both travel at the same speed
d. red light travels faster than violet light

6. 2
4. On which the intensity of light depends?
a. frequency
b. how much energy it has
c. how much of it is absorbed
d. wavelength
5. Which of the following is NOT an electromagnetic wave?
a. infrared
b. radio
c. sound
d. visible light
6. Among all the electromagnetic waves, which has the highest frequency
a. infrared
b. gamma rays
c. radio wave
d. ultraviolet light
7. Light is an electromagnetic wave. Which characteristic is common in all
electromagnetic waves in vacuum?
a. amplitude
b. frequency
c. speed
d. wavelength
8. Which electromagnetic wave is used in a microscope?
a. gamma rays
b. infrared
c. ultraviolet light
d. visible light
9. What kind of wave is light?
a. electromagnetic
b. longitudinal
c. mechanical
d. transverse
10. What is the reason why the Sun have the greatest apparent brightness among
the stars?
a. It has the highest surface temperature.
b. It is closest to the Earth.
c. It is farthest from the Earth.
d. Its color is yellow.

7. 3
Lesson
1
Color and Intensity of Light
in Terms of Its Wave
Characteristics
What’s In
In the previous module, you have learned about characteristics of sound,
concepts of wavelength, velocity and amplitude. This time you will study about light,
which is another form of energy. You will also know the nature of light in terms of its
wave characteristics.
But before that, let’s have a short review about our past lesson. Identify what is
described for each sentence by choosing the correct answer from the word bank.
Write your answers in your notebook/ on a separate sheet of paper.
1. It is how soft or how intense the sound is as perceived by the ear.
2. These are sound waves with frequency beyond 20,000Hz that cannot be
perceived by the human ear.
3. These are mechanical waves that need a medium to be propagated.
4. It is a special sound that forms patterns and are appealing to our Sense of
hearing.
5. It is created by a series of compression and rarefaction which result in
longitudinal waves.
6. It refers to the amount of energy a sound wave carries.
7. It is the standard unit of sound.
8. It is a distorted sound which is not pleasing to the ears.
9. It refers to the highness and lowness of sound.
Sound waves vibration mechanical wave pitch
Longitudinal wave loudness sound intensity decibel
Audible sound ultrasound noise music

8. 4
10. These are the sound waves within the 20 Hz – 20,000 Hz range which can
be perceived by the human ear.
Notes to the Facilitator
The activities in this module are arranged from simple to
complex in order to help the learners gradually master the
desired learning competency. Your support and guidance are
needed so that they will be able to perform the task later which
is to explain the color and intensity of light in terms of its wave
characteristics.

9. 5
What’s New
Directions. Find the words that are related to Light inside the Word Search Box.
Write your answers in your notebook/ on a separate sheet and describe each word.
A C O L O R S P E C T R U M Z
K D R R S T V U N I E A M B T
L F A W A V E L E N G T H Y P
M H N T G Y D R R S T H A N P
O G G I N L I 0 G R E E N J I
F R E Q U E N C Y B I Y U L N
R K A O N R T T F R T P G M D
Q L V I O L E T G T N W E N I
T M R R A I N B O W T D D P G
S L I G H T S R T Y M F K O O
B P B H B R I G H T N E S S L
C Q E I O E T X Z B L L R M Y
E R C J Q D Y E L L O W D K A
T S D K R Q A B M U H E A M S
S T F L P X S N B E G F C F D

10. 6
What is It
Life without light wouldn’t be possible. The Bible gives an account of the origin
of light. From the Book of Genesis 1:3, God said, “Let there be light”; and there was
light.
Man has studied the nature of light since the start of civilization. Plato and
Euclid believed that light was something given off by the eye. Aristotle thought of
light as something non-material that goes through the space between the eye and
the object seen. Pythagoras considered light to be very fine particles coming from a
luminous object. The Greek philosopher, Empedocles, asserted light to be a very
high-speed wave.
Several theories about light were proposed at different times and of different
scientists. But each theory has its limitations and cannot completely explain all the
observed phenomena of light.
In 1690, Christian Huygens proposed the wave theory of light. This theory
considered light to be a wave propagating in ether. A contemporary of Huygens, Sir
Isaac Newton, came up with his particle theory of light in 1704. According to this
theory, light consists of tiny particles emitted by a luminous object. Another scientist,
Max Plank came up with what is now known as the Dual-Nature of Light. He
explained that light can be a particle or a wave. Toward the end of the 19th century,
James Clark Maxwell proposed the Electromagnetic Theory of Light.
So, what is light? Light is all around us. It not only lets us see in the dark,
but its properties are also important to many aspects of our lives.
Colors of Light
Light or visible light is just a small portion of the electromagnetic spectrum that
can be perceived by the human eye. It lies between the infrared region and the
ultraviolet region. Light is made up of wavelengths of light, and each wavelength is a
particular color. The color we see is a result of which wavelengths are reflected back
to our eyes. The colors of visible light are red, orange, yellow, green, blue, indigo, and
violet. These different colors have specific frequencies and wavelengths. Red light has
the longest wavelength but has the lowest frequency. On the other hand, violet has
the shortest wavelength but has the highest frequency.
The wavelength and frequency of light are important properties of light. They
determine the energy of a photon of light. There exists a direct proportionality
between the frequency of light and its energy. Among the color components of white
light, violet has the greatest energy; red, the least energy.

11. 7
Intensity of Light
Another characteristic of light is intensity. In photometry (optics), or the
science of the measurement of light, light intensity is the measurement of light in
terms of its perceived brightness to the human eye.
Brightness of light depends on the source and the distance from it. Brightness
however, is qualitative and is dependent on the person’s perception. The more
intense the light is reaching us is, the “brighter” the light appears to be.
Quantitatively, brightness can be expressed as luminous intensity with a unit known
as candela. The unit expression came from the fact that one candle can
approximately represent the amount of visible radiation emitted by a candle flame.
However, this assumption is decades ago and therefore inaccurate.
James Clark Maxwell
Color of Light Size of Wavelength Frequency and Energy
red
yellow
green
violet
James Clerk Maxwell discovered
the Electromagnetic Theory of Light. He
combined the concepts of light,
electricity and magnetism to come up
with his theory forming electromagnetic
waves. Since these are waves, they also
exhibit different characteristics of
waves such as wavelength, frequency
and wave speed which you have
studied in the previous module. There
are different forms of electromagnetic
waves arranged according to frequency.
This arrangement of the
electromagnetic waves is known as
Electromagnetic spectrum. The visible
part of which is known as white light or
visible light.

12. 8
Proper lighting plays a significant role in our daily lives. For example, it makes
us able to read books, magazines and newspapers without putting much strain in
our eyes and without any discomfort. This happens when there is enough amount of
light falling on the material we are reading. It is also necessary to have good lighting
at home and in school to perform different activities rightly. Another example is when
we are able to cross the streets with the help of lighted lamp posts around us.
Otherwise, we will encounter road accidents. Contrary to that, poor lighting can be
a safety hazard and a health hazard. Poor lighting leads to poor quality of work and
may lead to accidents or injury.
Brightness or intensity and colors are special properties of light. These can be
observed in different phenomena such as rainbows, red sunset, and blue sky. You
can identify many other applications of light and colors as you become keen
observers of natural phenomena.
What’s More
Activity 1: My Spectrum Wheel
Materials Needed
 Color Spectrum
 Wheel Pattern
 Cardboard or illustration board
 Button fastener
 Glue or paste
Procedure
Part 1: Color Wheel
1. Copy the two art files that make up the wheel on the next pages on a
cardboard.
2. Cut along the lines drawn on the top wheel. The small window near the
center of the wheel should be completely cut out and removed.
3. Punch a hole at the center of the two wheels. You may use a button
fastener to secure the two wheels together one on top of the other, but
they should be free to rotate relative to each other.

13. 9
4. When you see a region of the Color spectrum show up in the open
window and the "W, F, E" that correspond to that region showing up
under the flaps, then you know that you have done it right.
Figure 1. Color Spectrum Wheel Pattern 1
Figure 2. Color Spectrum Wheel Patter 2
Source: K to 12 Science Grade 7 Learners Material. Pasig City: Bureau of
Learning Resources (DepEd-BLR), 2017.
Source: K to 12 Science Grade 7 Learners Material. Pasig City: Bureau of Learning
Resources (DepEd-BLR), 2017.

14. 10
Part 2: Characteristics of Light
1. Try out your Color Spectrum Wheel by positioning the innermost of
the flaps on COLOR SPECTRUM. This will simultaneously position
the other flaps to ENERGY, WAVELENGTH & FREQUENCY.
2. Turn the upper wheel and observe the combinations.
3. Fill in the table below with the corresponding combinations you
have observed using your Spectrum Wheel.
Table 1. Characteristics of Color Lights
Color
Spectrum
Energy (eV)
Frequency
(THz)
Wavelength
(nm)
Frequency x
wavelength
(m/s)
Red
Orange
Yellow
Green
Blue
Violet
With the use of your color spectrum wheel and your data from Table 1, answer
the questions below. Write your answer in your notebook/ on a separate sheet of
paper.
Guide Questions
1. Which color has the highest frequency?
2. Which color has the lowest frequency?
3. Which color has the shortest wavelength?
4. Which color has the longest wavelength?
5. What is the relationship between the wavelength and frequency of the
different colors?
6. How is energy related to frequency?

15. 11
7. What can you say about the speed of the different colors?
Activity 2: Intensity of light
In this activity, you should be able to see that the brightness of light is dependent
on the distance of the source.
Materials needed
 Flashlight
 Meter Stick
Intensity Distance from Light Source
1. Hold your flashlight and put it on.
2. Put off the light of your room.
3. Aim the flashlight on the wall, measure one meter away from it. Observe
the brightness of light.
4. Move the light source farther away from the wall by ½ meter. Observe the
brightness of light.
5. Move as far as you can in the room (by half meter).
6. Rank the observed brightness. Copy and complete this table in your
notebook.
Distance from the
Wall (m)
Observation Rank
1.0
1.5
2.0
2.5
3.0
How would you relate the apparent brightness of light with the distance from the
source?

16. 12
What I Have Learned
Directions. Complete the paragraph by choosing the correct answers found inside
the box and write them in your notebook/ on a separate sheet of paper.
wave wavelength straight light brightness
visible
spectrum
refraction of
colors of light
wave speed frequency prism
(1) ________________ has a wavelike nature. It is part of the electromagnetic waves
as the visible spectrum. The (2) ________________ is also known as white light. White
light undergoes dispersion when it passes through a (3) ________________. The
variations of refractive indices result to variations in the (4) ________________
dependent on the frequencies (and wavelength) of the color lights. This brings about
blue light being refracted more than the other color of lights, and thus, appears to
be bent. Light travels in a (5) _________________ line path in a particular medium. (6)
________________ characteristics of light are: (7) ________________, (8) ________________
and (9) ________________. (10) ________________ or intensity and colors are special
properties of light. These can be observed in different phenomena such as rainbows,
red sunset, and blue sky. You can identify many other applications of light and colors
as you become keen observers of natural phenomena.
What I Can Do
Directions. Write a short paragraph about the importance of light and how are you
going to apply it in your daily life. Write it in your notebook/on a separate sheet of
paper.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________

17. 13
Assessment
Direction: Write TRUE if the statement is correct, and FALSE if it is otherwise.
Remember to write your answers in your notebook/ on a separate sheet of paper.
1. If the light has a longer wavelength, it has a lower energy.
2. Light with a shorter wavelength has a higher energy.
3. Red from the color spectrum has the longest wavelength.
4. The color violet has the highest energy and frequency.
5. The color red has the highest energy and frequency.
6. The shorter the wavelength, the lower the energy.
7. The color red has the lowest energy and frequency.
8. White light consists of different colors.
9. As the frequency of light increases, the energy also increases.
10. As the wavelength of light becomes longer, the energy increases.
11. As the frequency of light increases, the wavelength becomes shorter.
12. As the frequency of light decreases, the wavelength becomes longer.
13. Dispersion is a phenomenon in which a prism separates white light
into its component colors.
14. Brightness or intensity and colors are special properties of light. These
can be observed in different phenomena such as rainbows, red sunset,
and blue sky.
15. As a wave, light is part of the electromagnetic waves as the visible
spectrum or white light.

18. 14
Additional Activities
Congratulations! You are almost done. For your final activity in this module,
draw and color the rainbow following the given instructions. Draw it in your
notebook/ on a separate sheet of paper.
Red - outermost part with longest wavelength.
Violet - innermost part, should be with the shortest wavelength.
Answer Key
Additional
Activities
Drawing
of
colored
rainbow
What
I
Can
Do
Answer
may
vary
Assessment
1.
True
11.
True
2.
True
12.
True
3.
True
13.
True
4.
True
14.
True
5.
False
15.
True
6.
True
7.
True
8.
True
9.
True
10.
False
What
I
Have
Learned
1.
light
2.
visible
spectrum
3.
prism
4.
reflections
of
colors
of
light
5.
straight
6.
wave
7.
frequency
8.
wavelength
9.
wave
speed
10.
brightness
What’s
More
1.
Violet
2.
Red
3.
Violet
4.
Red
5.
Inversely
proportional
6.
Directly
proportional
7.
Their
speed
are
almost
the
same
What’s
More
Distance
from
the
wall(m)
Observation
Rank
1
1.5
2
2.5
3

19. 15
References
Books
K to 12 Science Grade 7 Learners Material. Pasig City: Bureau of Learning Resources
(DepEd-BLR), 2017.
Ferriols-Pavico, J. Ma., et. al. (2013). The Nature of Light. Exploring Life Through
Science Series. 232-235. 927 Quezon Avenue, Quezon City. Phoenix
publishing house, inc.
Electronic Sources
https://en.wikipedia.org/wiki/James_Clerk_Maxwell
https://phys.libretexts.org/Courses/University_of_California_Davis/UCD%3A_Phy-
sics_7C__General_Physics/10%3A_Electromagnetism/10.4%3A_Electromag-
netic_Waves%3A_Light/3._Energy_and_Intensity_of_Light
https://www.sciencelearn.org.nz/resources/47-colours-of-light
What’s
More
Color
spectrum
Energy
(eV)
Frequency
(THz)
Wavelength
(nm)
Frequency
x
Wavelength
(m/s)
Red
422
700
295,400
Orange
484
620
300,080
Yellow
517
580
299,860
Green
566
530
299,980
Blue
638
470
299,860
Violet
744
400
297,600
What's
In
1.
loudness
2.
ultrasound
3.
soundwave
4.
music
5.
vibration
6.
sound
intensity
7.
decibel
8.
noise
9.
pitch
10.
audible
sound
What
I
Know
1.
A
2.
A
3.
C
4.
B
5.
C
6.
B
7.
C
8.
D
9.
A
10.
B
What’s
New
1.
Color
Spectrum
2.
Energy
3.
Wavelength
4.
Frequency
5.
Red
6.
Orange
7.
Yellow
8.
Green
9.
Blue
10.
Indigo
11.
Violet
12.
Rainbow
13.
Intensity
14.
Brightness
15.
Light

20. For inquiries or feedback, please write or call:
Department of Education - Bureau of Learning Resources (DepEd-BLR)
Ground Floor, Bonifacio Bldg., DepEd Complex
Meralco Avenue, Pasig City, Philippines 1600
Telefax: (632) 8634-1072; 8634-1054; 8631-4985
Email Address: blr.lrqad@deped.gov.ph * blr.lrpd@deped.gov.ph