Shopping on the Internet
As many of us know, the Internet has become much more than just an information
research tool. With new dot-com companies popping up on a daily basis
and many brick and mortar companies going digital in an effort to lure
consumers into purchasing their products, we must be careful of what we
see and read on the Internet.
This activity is designed to get your students thinking about what makes
one brand of shampoo better than the next. Why should they purchase this
brand and not that brand? Can they truly make an informed consumer decision
based solely upon what they see and read on the Internet?
Step 1:
Open up your computer's Web browser and select the bookmarked hyperlink/URL
for the Pert Shampoo Web site (http://www.pertplus.com/pert_index.asp).
Click on the graphic that says "Got Questions?" This will take
you to another Web page that deals with the specific types of shampoos
that Pert manufactures for various types of hair conditions. Provide your
students with a FOCUS FOR MEDIA INTERACTION, asking them to read
each "Hair Dilemma" to see what Pert recommends its consumers
use to solve their hair problems. Have your students select the shampoo
that they think is best for them and their hair condition. Take a random
sample of your class's selections to see what style of shampoo they would
select based only on what they saw and read at the Web site.
Step 2:
Click on the bookmarked hyperlink/URL for Head and Shoulders Web site
(http://www.headandshoulders.com/usa/).
At the top of the page, there is a hyperlink button titled "Our Shampoos."
Direct your students to click on this hyperlink. Provide your students
with a FOCUS FOR MEDIA INTERACTION, asking them to roll their mouse
over each different type of shampoo and again read the product description
to see which one is best for their particular hair type and condition.
Again, take a random sample of your class's selections to see what style
of shampoo they would purchase based only on what they read.
Step 3:
Click on the bookmarked hyperlink/URL for the Neutrogena Web site (http://www.neutrogena.com/Home.asp).
After the Web site introductory animation, move your mouse to the top
left side of the Web page and click on the hyperlinked word "Products."
Once the hyperlink rolls down, move your mouse over the hyperlinked word
"Hair Care." Once your students are at the Web page for hair
care products, provide your students with a FOCUS FOR MEDIA INTERACTION,
asking them to once more check out the product descriptions for each of
Neutrogena's different shampoos to see which brand they would select from
the Neutrogena product line. Again, take a random sample of your class's
selections to see what style of shampoo they would purchase based only
on what they read.
Step 4:
Ask your students which shampoo selections do they think would do the
best job cleaning their hair. How would they be able to determine which
shampoo does the best job? Does a $10.00 bottle of shampoo clean better
than a $2.00 bottle of shampoo? Does paying more for your shampoo mean
you're getting a better product? Do they know how soaps and detergents
work? What chemical reaction makes a soap/detergent/shampoo remove dirt/grease/oil
from their clothes/skin/hair? After getting your students' reactions to
these questions, direct your students to their lab stations for the next
Introductory Activity.
Step 5:
In this activity, the students will be exposed to how soaps/detergents
react when they are exposed to water for the purpose of cleaning and removing
dirt/grease/grime from either their clothes/body/hair.
Procedure:
- Provide each group with the materials for this activity (listed
at right)
- Direct each group to pour approximately 5cm of milk into their petri
dish.
- Instruct each group to add one drop of each food color to the milk,
making sure that they avoid the center of the petri dish and stay
as close as possible to the sides of the petri dish. (The best way
to describe this step is to tell your students to place one drop at
12 o'clock, one drop at 3 o'clock, one drop at 6 o'clock, and the
last drop at 9 o'clock.)
- Have each group soak one end of their tooth pick in the detergent.
- Have each group place the detergent soaked end of the toothpick
into the center of the petri dish until it touches the bottom of the
dish.
- Ask the students to observe the petri dish and its contents for
the next four minutes.
- Discuss with the class what happened and why. Accept their answers
as possible explanations. However, do not clarify any concepts at
this point in time.
- Explain to your students that they are going to view a segment of
film that will help them understand more clearly what happened to
the milk and food coloring when they placed the detergent laden toothpick
into the petri dish. (See Step 7 in the Learning Activity Section
of this lesson for a detailed explanation of what chemical reaction
takes place in the petri dish.)
Step 1:
Insert the video Organic Chemistry 2, Episode # 8 "Soap" into
the VCR.
Step 2:
Tell your students they are to watch the video segment and see if it helps
them understand what happened in the Introductory Activity. Provide your
students with a FOCUS FOR MEDIA INTERACTION, asking them to watch
the segment to identify why water is such a poor cleansing agent, and
to explain the process of dissolving polar molecules. PLAY the
tape starting at the visual cue of a cartoon character standing in front
of a bath with the audio cue, "Around 1840, the first bathtubs were
imported to North America." PAUSE the Video as the narrator
says, "In plain water, ring around the collar, a fat, is plain stubborn.
It just won't dissolve." Discuss with your students why water alone
does not remove the oils from human skin, which are typically found in
the ring of a light colored shirt collar. (The fat does not dissolve in
the water.)
Discuss with your students if they think that the ring around the shirt
collar and the ring around the tub are the same or not and why this phenomena
happens to both items that are made of fabric and items that are made
from porcelain or plastic.
Step 3:
Provide your students with a FOCUS FOR MEDIA INTERACTION, asking
them to listen for the definition of the word "dissolve" and
determine why only certain types of molecules dissolve. RESUME
the video at the pause point, then PAUSE again at the visual cue
of the cartoon image of a shirt in a sink at the narration cue, "Water
and oil don't mix." At this point, demonstrate this concept by pouring
some oil into a beaker containing water. Shake the beaker or use a stirring
rod. Have your students observe what takes place and discuss their observations.
(During each attempt, the water and oil do not dissolve in each other.)
Discuss with your students why they think oil and water do not mix. What
makes them continually want to separate?
Step 4:
Provide your students with a FOCUS FOR MEDIA INTERACTION, asking
them to watch the next video segment and look for the molecular structure
of the fat molecule. They are to complete the drawing on the worksheet
at their individual desks. RESUME the tape at the last pause point,
then PAUSE the video at the visual cue of a fat molecule surrounded
by water molecules at the narration cue, "Both fat and oils are non-polar,
and as such cannot participate in hydrogen-bonding with water." Discuss
with your students the difference between saturated and unsaturated fats
as discussed in the film. If your students do not make this connection
the first time, just REWIND the segment and replay it for further
clarification. (The fat molecules have a long hydrocarbon chain with no
double bonds and are said to be saturated with hydrogen. The oil and grease
molecules have a varying number of double bonds, and are identified as
unsaturated.) Give the students an opportunity finish their drawings and
to label their drawing of the fat/oil molecule.
Step 5:
Provide your students with a FOCUS FOR MEDIA INTERACTION, asking
them to determine the effect that detergents have on fat molecules. They
will need to explain how the fat molecules become "dissolvable"
or emulsified in water. (An emulsion is a suspension of microscopic oil
droplets in water.) RESUME the video at the pause point, then PAUSE
at the visual cue of the soap molecule at the narration cue, "The
soap molecule has an ionic head and a non-polar tail." At this point,
discuss with your students the transition of the fat molecule to a soap
molecule with the addition of a base of sodium hydroxide. (The soap molecule
has a hydrophobic region, which is hydrocarbon in structure and non-water
attracting in its character, and a hydrophilic region, which will dissolve
in water.) Allow your students ample time to complete the worksheet by
labeling the soap and detergent molecules.
Step 6:
Provide your students with the next FOCUS FOR MEDIA INTERACTION,
asking them to look for the formation of micelles and to be ready to explain
how the dirt is "swept away." RESUME the tape at the
last pause point and STOP the tape at when the narration says,
"It is converted into discrete, suspended blocks, transported by
water, and swept away." Check for comprehension, and discuss with
your students how soap molecules clean. Have your students write down
their ideas and descriptions in their notebooks or on the back of Worksheet
#1.
Step 7:
Refocus your class's attention to the Introductory Activity. Discuss with
your class what happened to the food coloring when a detergent was introduced
to the milk. (Currents of color quickly move out in all directions from
the center of the petri dish. Swirling movements of separate colors are
seen across the surface of the milk during the first two minutes. Within
the next two minutes, the colors begin to mix and form a final gray mixture.)
Discuss with your students that the colors remain separate at first because
of the fat in the milk. These fatty drops do not mix with the watery food
coloring, therefore the colors are kept apart. The colors move outward
due to the surface water molecules' pull on the molecules of color with
an equal force in all directions. By placing the soap in the center of
the petri dish, they weakened the pull of the water molecules in the center
of the dish, and the stronger clinging water molecules on the opposite
sides of the color molecules pulled them across the surface of the water
towards the edge of the petri dish. The soap or detergent, a surfactant,
lowered the surface tension of the water. As the drops of fat are broken
into smaller particles, micelles, by the detergent, they spread out, allowing
more of the food coloring and milk to mix.
Step 1:
Explain to your students that the ability of certain molecules to act
as a cleaning agent has a direct relationship to their molecular structure,
just like what we saw in the learning activity. Shampoos are cleaning
agents and can be tested to obtain empirical data about their characteristics
and relative effectiveness as a cleaner. A number of variables will be
tested, including the pH levels, flash volumes, foam retention, dispersion,
and the viscosity of each shampoo selected earlier. From their studies,
the class can begin to draw a limited number of scientific conclusions.
The open-endedness of this hands-on activity allows them to explore as
many different shampoos as they desire. (If you like, have your students
bring in their favorite shampoo. This will provide the class with a adequate
sampling with which the students may begin their investigation.)
Step 2:
Direct your students to break up into their lab groups and arrange the
their lab stations for the next experiment.
Step 3:
Distribute the Worksheet #2 to each student in the class. Instruct your
students to follow the steps on Worksheet #2. This lab is designed so
that your students can collect empirical data about the character and
relative effectiveness of various shampoos. It is important as you circulate
through the room that you remind your students that the data from each
group experiment can be compared, and a consumer effectiveness report
can be prepared on each of the various shampoos tested. These results
can be published either as a computer-generated report or as a student
designed and created consumer information Web site.
Step 4:
After each group has finished testing and recording the results for
their five shampoos, have them once again return to their computers
and click on the bookmarked hyperlink/URL for the Street Cents Web site
(http://www.halifax.cbc.ca/streetcents/show/more/show_08_00/shampoo.html#link8).
Provide your students with a FOCUS FOR MEDIA INTERACTION, asking
your students to read over the following Web site paying particular
attention to information about surfactants in shampoos and what each
one does. Ask them to look at their results for the lab portion of this
activity and determine, based on the ingredients of their shampoos,
which ones truly are worth the expenditure and which ones are not. Have
them determine, based on their reading and the ingredients listed on
each shampoo bottle, which shampoos are and are not harmful to their
hair even if the companies say the product is meant to treat their hair
condition.
Step 5:
At the bottom of the Street Cents Web page, there is a small blurb about
a Consumer Reports test and which shampoos their test has determined
to be the best on the market. If you desire, have those shampoos on
hand and have each group perform the testing phase all over again. This
time, each group could do one shampoo and report their results back
to the class.
ART
Students can invent their own brands of soap. Using solid vegetable
shortening and a 250ml beaker, add 10ml of ethanol and 5ml of 6M NaOH
solution (1.2 gms of NaOH in 5ml of water). Using a hotplate, heat the
mixture and stir for 15 minutes. While heating, students can add ingredients
to the soap: color, scent, or even plastic surprises.
SOCIAL STUDIES
Research soapmaking in the 19th century and early 20th century. Write
down a systematic procedure for making soap.
FAMILY CONSUMER SCIENCES AND FINE ARTS
Have students create their own bars of soap using the systematic procedure
they discovered during their social studies class.
Have students make various shaped bars of soaps using baking molds.
LANGUAGE ARTS
Students can keep a journal of all the foods that they eat for one week.
They can then analyze what percentage of their weekly diet consists
of fat.
Have your students write a pamphlet on the health risks related to a
high fat diet.
Have your students research a female scientist, and write a one-page
report on their life and contributions to the concepts covered in this
lesson.
Female Scientists
- Jacqueline K Barton
- Emma Perry Carr
- Rachel L. Carson
- Gertrude T Cori
- Stephanie Kwolek
- Kathleen Nauss
- Brigit Vennesland
- Students can visit a local eatery and interview the kitchen staff
to see how they clean the kitchen equipment on a daily basis.
- Students can visit the school cafeteria to learn how they clean
the utensils and cafeteria trays and learn about the cleaning equipment
used in the kitchen.
- Visit a local advertising company to investigate how marketing agencies
market their products in an effort to entice consumers to purchase
their clients' products.
- Invite a local doctor or surgeon to the classroom to speak to your
students about cleaning materials and procedures used in hospitals
and doctor's offices to ensure clean and sterile environments for
his/her patients.
- Students can bring in ocean water to see if soap is as effective
in salt water as it is in natural water.
- Students can speak with the school's custodians about how various
areas of the school building are cleaned differently and what types
of cleaning solutions and procedures are used to keep their school
clean.
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