Transmittance, Absorbance & Color:
Gummy Bears & Lasers Lab
THIS BELONGS TO:
Group: F ~ G ~ H
1
Transmittance, Absorbance & Color
BACKGROUND NOTES:
A common _________________________, is that color is a property of matter. This underlying
misconception leads to all manner of confusion – like the idea that when white light passes
through a green object to cast a green glow on the paper, the object is adding color to the
otherwise clear, “natural” light. THIS IS NOT CORRECT; instead different colored lights exist at
different ____________________ and matter will either ________________ (let pass) or
______________ certain colored lights, depending on its chemical properties.
There are three main vocabulary words you must know for this lab:

________________________ : light that passes through an object

_______________________: light that bounces back to the original source (note: this will not
occur in our gummy bear laser lab)

_______________________: light that neither reflects or transmits from an object, light that
is “trapped” inside of the object
In this lab, we will be working with two types of light: ___________________ lights as well as
________ and ________ laser lights.
Most of the light you are familiar with is white light, such as
our white LED lights, which are composed of many colors,
or wavelengths. When ______________hits an object, the
object _______________ absorbs, reflects or transmits
certain wavelengths. The way that light interacts with an
object depends on the wavelength(s) of light and the
nature of the atoms in the object.
When ___________light, which is monochromatic (composed of a single color or wavelength) hits
something, it is absorbed, converting light energy into heat, it is reflected, or it is transmitted.
A material will absorb frequencies of light that match the frequency at which electrons in the
atoms that make up a material vibrate. Because different materials are made up of atoms whose
electrons vibrate at different frequencies, different materials absorb different frequencies of
2
light. This breaks up the notion that the reason light passes through a material or not because of
its “thickness”.’
Light that a material does not absorb is either reflected, or transmitted. The way in which we
see color is due in large part to the way light interacts with matter. So the color was never in the
object…only in the light that shines upon it and ultimately is reflected to our eyes.
The Question
What is the effect of the _____________ of the ____________ and the _____________ of the
gummy bear on whether certain visible wavelengths are absorbed or transmitted?
3
H
Hypothesis:
Part 1 – LED WHITE LIGHT
A. If we shine a WHITE LED light on a CLEAR gummy bear THEN there will be a [red / green
/ white] SHADOW transmitted and all other colors will be absorbed.
CLEAR
B. If we shine a WHITE LED light on a RED gummy bear THEN there will be a [red / green /
white ] SHADOW transmitted and all other colors will be absorbed.
RED
C. If we shine a WHITE LED light on a GREEN gummy bear THEN there will be a [red / green
/ white ] SHADOW transmitted and all other colors will be absorbed BECAUSE
______________________________________________________________________________________
GREEN
_____________________________________________________________________________________ .
Part 2 – RED LASER LIGHT
A. If we shine a RED LASER light on a CLEAR gummy bear THEN there will be a [red / green
/ white] SHADOW transmitted and all other colors will be absorbed.
CLEAR
B. If we shine a RED LASER light on a RED gummy bear THEN there will be a [red / green /
white ] SHADOW transmitted and all other colors will be absorbed.
RED
C. If we shine a RED LASER light on a GREEN gummy bear THEN there will be a [red / green
/ white ] SHADOW transmitted and all other colors will be absorbed BECAUSE
______________________________________________________________________________________
_____________________________________________________________________________________ .
4
GREEN
Part 3 – GREEN LASER LIGHT
A. If we shine a GREEN LASER light on a CLEAR gummy bear THEN there will be a [red /
green / white] SHADOW transmitted and all other colors will be absorbed.
CLEAR
B. If we shine a GREEN LASER light on a RED gummy bear THEN there will be a [red /
green / white ] SHADOW transmitted and all other colors will be absorbed.
RED
C. If we shine a GREEN LASER light on a GREEN gummy bear THEN there will be a [red /
green / white ] SHADOW transmitted and all other colors will be absorbed BECAUSE
______________________________________________________________________________________
GREEN
_____________________________________________________________________________________.
Variables:
Type of
Variable
Independent
Definition of type
The thing we change on
purpose to ask if it will make a
difference
What it is in this lab [CIRCE THE
CORRECT ANSWERS]
COLOR (OF GUMMY BEAR & LASER)
WHAT COLOR IS ABSORBED
WHAT COLOR IS TRANSMITTED
Dependent
The thing we measure last
COLOR (OF GUMMY BEAR & LASER)
WHAT COLOR IS ABSORBED
WHAT COLOR IS TRANSMITTED
Constant(s)
The things we keep the same in
order to be fair
Materials:
1 Green Laser
1 Red Laser
1 White LED
5
1 Each: red, green Gummy Bears
1 sheet of plain white paper
PROCEDURE:
SET-UP (make sure your lab area looks like mine)
Figure 1. Put your clear, red, and green gummy bears in a row
on a white piece of paper.
PART 1 – WHITE LED LIGHT
1. Take a look at the white LED - recall that white light is composed of many (“all”)
wavelengths or frequencies of light.
2. Shine the white LED at the CLEAR gummy. What color is the shadow that is on the other
side of the clear gummy bear (transmitted)? What colors are not in the gummy bear’s
shadow (aka what colors are absorbed by the gummy? FILL OUT ON YOUR DATA TABLE
3. Now shine the white LED at the GREEN gummy. What color is the shadow that is on the
other side of the green gummy (transmitted)? What colors are not in the gummy bear’s
shadow (aka what colors are absorbed by the gummy? FILL OUT ON YOUR DATA TABLE
4. Now shine the white LED at the RED gummy. What color is the shadow that is on the other
side of the red gummy (transmitted)? What colors are not in the gummy bear’s shadow
(aka what colors are absorbed by the gummy? FILL OUT ON YOUR DATA TABLE
SAFETY DIRECTIONS: PUT YOUR HAND ON THE OPPOSITE
SIDE OF THE GUMMY BEARS TO BLOCK THE LIGHT FROM
TRAVELING.
BE SURE THAT THERE IS NO PERSON ON THE OTHER END
OF THE LIGHT.
PART 2 – RED LASER LIGHT
1. Take a look at the RED laser- recall that red light is composed of a single frequency of
wavelength (700nm). Recall that if you look on color wheel, red is opposite to green.
6
2. Shine the RED laser at the CLEAR gummy. What color is the shadow that is on the other
side of the clear gummy bear (transmitted)? What colors are not in the gummy bear’s
shadow (aka what colors are absorbed by the gummy? FILL OUT ON YOUR DATA TABLE
3. Now shine the RED laser at the GREEN gummy. What color is the shadow that is on the
other side of the green gummy (transmitted)? What colors are not in the gummy bear’s
shadow (aka what colors are absorbed by the gummy? FILL OUT ON YOUR DATA TABLE
4. Now shine the RED laser at the RED gummy. What color is the shadow that is on the other
side of the red gummy (transmitted)? What colors are not in the gummy bear’s shadow
(aka what colors are absorbed by the gummy? FILL OUT ON YOUR DATA TABLE
SAFETY DIRECTIONS: PUT YOUR HAND ON THE OPPOSITE
SIDE OF THE GUMMY BEARS TO BLOCK THE LASER FROM
TRAVELING.
PUT THE TIP OF THE LASER TO THE GUMMY BEAR.
BE SURE THAT THERE IS NO PERSON ON THE OTHER END
OF THE LIGHT.
PART 3 – GREEN LASER LIGHT
1. Take a look at the GREEN laser- recall that green light is composed of a single frequency
of wavelength (500nm). Recall that if you look on color wheel, green is opposite to red.
2. Shine the GREEN laser at the CLEAR gummy. What color is the shadow that is on the
other side of the clear gummy bear (transmitted)? What colors are not in the gummy
bear’s shadow (aka what colors are absorbed by the gummy? FILL OUT ON YOUR DATA
TABLE
3. Now shine the GREEN laser at the GREEN gummy. What color is the shadow that is on
the other side of the green gummy (transmitted)? What colors are not in the gummy
bear’s shadow (aka what colors are absorbed by the gummy? FILL OUT ON YOUR DATA
TABLE
4. Now shine the GREEN laser at the RED gummy. What color is the shadow that is on the
other side of the red gummy (transmitted)? What colors are not in the gummy bear’s
shadow
Results
Part 1 – White LED
7
Color of light
Color of Gummy
Bear
Clear
White (all
wavelengths)
White (all
wavelengths)
White (all
wavelengths)
Color transmitted (shadow of gummy)
Red
Green
Part 2 – RED laser
Color of light
Red (700nm)
Color of Gummy
Bear
Clear
Red (700nm)
Red
Red (700nm)
Green
Color transmitted (shadow of gummy)
Part 3 – GREEN laser
Color of light
Green (500nm)
Color of Gummy
Bear
Clear
Green (500nm)
Red
Green (500nm)
Green
Color transmitted (shadow of gummy)
CONCLUSION – write on a sheet of loose-leaf and staple on






Restate the lab’s question and your hypothesis
State if your hypothesis were supported or not supported
Summarize the methods
Explain what you observed
How do these results describe how color works as a form of energy? Be sure to include
the words “absorbance,” “transmitted” and “wavelength” somewhere in your answer.
Describe any limitations of this model and/or future ideas for future experiments
Self and Peer Assessment Performance Rubric
4
3
SELF Assess
I was all FOUR of the
I was THREE of the
2
I was TWO of the
1
I was ONE or less of
8
Performance
following
characteristics:
 On-task/did
not distract
others
 Completed
work
 Took detailed
observations
 Helped
others in
group when
needed
following
characteristics:
 On-task/did
not distract
others
 Completed
work
 Took detailed
observations
 Helped
others in
group when
needed
following
characteristics:
 On-task/did
not distract
others
 Completed
work
 Took detailed
observations
 Helped
others in
group when
needed
the following
characteristics :
 On-task/did
not distract
others
 Completed
work
 Took detailed
observations
 Helped
others in
group when
needed
4
3
2
1
PEER Assess
Performance
This person was all
FOUR of the
following
characteristics:
 On-task/did
not distract
others
 Completed
work
 Took detailed
observations
 Helped
others in
group when
needed
This person was
THREE of the
following
characteristics:
 On-task/did
not distract
others
 Completed
work
 Took detailed
observations
 Helped
others in
group when
needed
This person was
TWO of the following
characteristics:
 On-task/did
not distract
others
 Completed
work
 Took detailed
observations
 Helped
others in
group when
needed
This person was ONE
or less of the
following
characteristics:
 On-task/did
not distract
others
 Completed
work
 Took detailed
observations
 Helped
others in
group when
needed
______/ 8 pts
9
e:&_________________________________________&&&&&&Group:&___________________&&&&Date:&____________________&
&Title:&_______________________________________________________________________________&
b Report Rubric
All three variables are
Two of three variables are
correct and linked to the
identified and linked to the lab
effects each will have on the activity.
lab activity.
Step-by-step layout is
evident. Procedure is well
written, provides detailed
information on lab.
Includes the question to be
answered by the lab.
States a hypothesis that is
based on research and/or
sound reasoning
Title is relevant.
Excellent (4 pts)
Results are mostly supported
by data collected and
graphed. Graph is clean and
shows a representation of the
lab.
Step-by-step layout is evident.
Procedure is written, provides
some detailed information on
lab.
Two of the three Excellent
Conditions are met.
Hypothesis is sound but does
not completely cover a
testable statement.
Good (3 pts)
Conclusion identifies and
Conclusion does not
analyzes some of the aspects support lab or was not
of the lab. There are some
written.
grammatical errors in writing
that make it difficult to
understand.
Some results are supported
by data collected. Graph is
difficult to understand and
does not completely show a
good representation of the lab.
One of three variables are
identified. However, incorrect
variables affect lab activity
outcome greatly and skew
results.
Step-by-step layout of lab is
evident. Procedure is written,
provides little detailed
information on lab.
One of three Excellent
Conditions are met.
Hypothesis is not supported
by a testable statement.
Statement lacks reasoning
and/or research.
Fair (2 pts)
Data is not accurately
collected or graphed.
Graph is missing or does
not supported any aspect
of the lab.
None of the variables are
identified. Lab activity is
not testable.
Materials and Procedure
are not written/difficult to
identify. Procedure lacks
detailed information to
support the lab.
None of the criteria were
met. Question and
hypothesis are not
evident.
Poor (1 pt)
and
othesis
ults/Data
Results are supported by
data collected and graphed.
Graph is neat, clean and
shows a true representation
of lab.
Conclusion mostly identifies
and analyzes all aspects of
lab. Well written and hits most
Scientific Method points.
There are few grammatical
errors.
ables
pendent,
endent &
stant)
rials and
edure
clusion
Conclusion identifies and
analyzes all aspects of lab.
Well written and hits all
Scientific Method points.
There are no grammatical
errors.
de:&_____________&
Five%
Criteria%
Score& Percent&
20&
100&
19&
97&
18&
94&
17&
91&
16&
88&
15&
85&
14&
82&
13&
79&
12&
76&
11&
73&
10&
70&
9&
67&
8&
64&
7&
61&
6&
58&
5&
55&
&
her&Comments:&&
________________________________________________________________________________________________________________________________
________________________________________________________________________________________________________________________________
________________________________________________________________________________________________________________________________&
10