Download The Chemistry of - Cleveland State University

The Chemistry of
Health and Wellness:
A Hands-on Program
An Educational Demonstration Package
Prepared by the
Cleveland Section
of the
American Chemical Society
National Chemistry Week 2004
Overview
Chemistry keeps us Healthy, Well-thy and Wise! Fuel the body, fight the germs, and
feel great when you fire up your brain with chemistry! Develop your chemistry fitness
by joining us for an hour of hands-on experiments to celebrate National Chemistry
Week! While conducting hands-on experiments, students will learn about high-tech
fabrics, UV protection from sunscreens, hot and cold compresses, new and old broken
bone casting materials, spreading of germs, and the detection of calcium, iron, starch,
Vitamin C in foods.
Table of Contents
Page
Checklists
4
Required Supplies
7
Experimental Setup
10
Opening Session
13
Closing Session and Clean Up
41
Acknowledgments
The National Chemistry Week (NCW) programs of the Cleveland Section ACS began in
1994 with an idea to put together a scripted program that could be performed at any local school
or library. This idea has expanded to become the centerpiece of Cleveland Section's NCW
activities, which has received national recognition from the American Chemical Society. In
2004, the Cleveland Section volunteers will perform over sixty demonstrations at libraries,
schools, and other public sites. Continuing our relationship that started in 2001, the Cleveland
Section will also be providing training and materials for Cleveland-area teachers, at the
Cleveland Regional Council of Science Teachers’ Fall Conference, so that they can conduct
additional programs in their own classrooms.
This library/school program and other NCW events are the result of the hard work of many
dedicated and talented volunteers. It all starts with our local section NCW Planning Committee.
The Committee develops a theme for the program; recommends, tests, and reviews activities &
experiments; writes a script; collects supplies and materials; prepares the kits; recruits sponsors
and volunteers; contacts libraries and schools; and schedules shows. This Committee, as well as
the rest of the Section's NCW activities, was overseen by the Cleveland Section's NCW
coordinators for 2004, Lois Kuhns and Kat Wollyung. Committee members include Paula Fox,
Mark Waner, Don Boos, Marcia Schiele, Shermila Singham, John Pendery, Rich Pachuta, David
Ball, Jesse Bernstein, Helen Mayer, Fen Lewis and Betty Dabrowski. Additional credit and
thanks is given to all of the many GAK (Grand Assembly of Kits) Day volunteers, including the
John Carroll University ACS Student Affiliates, who gave up a Saturday in September to help
count, measure, and assemble all of the necessary materials for our demonstration kits.
Our NCW efforts reach many children year because of various sponsors who have donated
money, materials, and/or services to the Cleveland Section specifically for National Chemistry
Week. We are especially grateful to the NASA Glenn Research Center, John Carroll University,
the Cuyahoga County Public Libraries, W. L. Gore and Associates, Inc., 3M Company, Bonne
Bell, Inc., Discount Drug Mart (Brunswick, OH) and other anonymous sponsors for their
numerous contributions and support.
Last and most important, we thank all the volunteers who donate their time and expertise.
Without the dozens of dedicated chemical professionals to lead these activities, there would be
no Cleveland Section NCW program.
National Chemistry Week 2004 - Cleveland Section
2
Overview
Demonstrator’s Guide
How Experiment Write-ups are Organized
The materials and set-up of the demonstrations are located in the introduction section of this
packet. Then, each experiment write-up is presented as follows:
• Background Information for Demonstrators
• Demonstration Instructions
• Experiment Conclusions
• Additional Information If Needed – You obviously do not need to cover all of this
material with your students. Pick out what you are comfortable explaining.
Presentation Overview
This section describes the basic presentation technique used during the demonstrations. This is a
guideline only as the technique may vary for some experiments. Make sure you follow the
instructions given in each experiment.
1. Introduce experiment.
2. Do your demonstration piece.
Note:
Many experiments require you to perform the experiment to show the
students what to do on their own.
3. Have the students do their experiment.
Note:
For some experiments your demonstration and the student’s hands-on work
are nearly simultaneous. You are leading them as they perform the
experiment.
4. Some experiments will be done by all students. For others, there will be one experiment that
will be shared by all students at the table. In a few cases, only the demonstrator will perform the
experiment. You are encouraged to get student helpers for the demonstrator-only experiments.
MAKE SURE TO FOLLOW ALL DIRECTIONS IN EXPERIMENTS
Some experiments may have special safety concerns due to the materials being used. Any safety
concerns are listed in the section for that experiment. Any MSDS’s necessary would typically
be found in the Appendix; however, there are none necessary for this year’s program.
For information about the American Chemical Society’s NCW safety guidelines, visit
www.acs.org/portal/Chemistry?PID=acsdisplay.html&DOC=ncw%5Csafetyguidelines.html
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Checklists
Demonstrator’s Guide
Demonstration Check-Off List
The next few pages list suggested activities to complete for the program.
Activities To Do Before the Day of the Demonstration
4 When Complete
Read through this packet to familiarize yourself with the experiments
‰
Contact Kat Wollyung at [email protected] or Lois Kuhns @
[email protected] with any questions.
‰
Collect the materials you need to bring with you to the demonstration.
The materials list is on page 7.
‰
Contact the children’s librarian:
‰
¾ Ask the room to be arranged with 6 tables around a front table
¾ Ask to have 5 chairs around each of the 6 tables
¾ Ask for all the tables to be covered with newspapers and for extra
paper towels for each table.
¾ Ask about availability of demonstration materials from list of page 7
(ex. paper towels, newspaper)
¾ Make sure that the room is available before and after the program for
set up and clean up.
Activity To Do AT LEAST ONE DAY BEFORE the Demonstration
4 When Complete
There are no specific experimental preparations to do before coming to
this year’s program.
‰
Continued next page
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Checklists
Demonstrator’s Guide
Activities To Do When You Get To The Library
4 When Complete
Arrive approximately 1 hour before demo time to allow for set up
‰
Introduce yourself to the children’s librarian
‰
Ask the librarian how many students are pre-registered (designed for 30)
‰
Confirm that the tables and chairs are set up properly
‰
Confirm that all tables are covered in newspaper and have paper towels
‰
Obtain those supplies from list on page 7 if provided by library
‰
Complete Demonstration Set-Up for all demonstrations: (see “Activities
to Do On-Site Prior to Demonstration” on page 10)
‰
Note: This set-up is estimated to take 30-45 minutes.
Set out the literature (for example: ChemMatters magazines, Celebrating
Chemistry newspapers, and related handouts for this year)
Activities To Do During The Demonstration
‰
Timing
Welcome the students and parents as they enter the room.
-
Hand out goggles and help adjust to the correct fit (if necessary).
-
Assess number of students per table and adjust to 3 - 5 per table. Record the
number of students and adults.
-
Continued next page
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Checklists
Demonstrator’s Guide
Activities To Do During The Demonstration (Continued)
Timing
Complete the Opening Session Introduction
4 min.
Perform demonstrations
¾ Experiment 1: High Tech Fabrics – Fabric Breathability
8 min.
¾ Experiment 2: Sunscreen
5 min.
¾ Experiment 3: Soothing the Pain - Hot and Cold Compresses
<5 min.
¾ Experiment 4: Watch Out for Germs! - Glow Germ with UV Light
<5 min.
¾ Experiment 5: Casting a Broken Finger
10 min.
¾ Experiment 6: Finding the Iron in Cereal
5 min.
¾ Experiment 7: Detection of Calcium in Milk
5 min.
¾ Experiment 8: Testing for Carbohydrates - Starch
<5 min.
¾ Experiment 9: Vitamins! Vitamins!
<5 min.
Complete the Closing Session information, collect goggles, hand out literature
<5 min.
Total Time:
~ 60 min.
Activities To Do Immediately After The Demonstration
4 When Complete
Clean up as indicated in the Clean Up section (page 41)
‰
Record the number of adult and student participants
‰
Give any leftover literature to the librarian (library kits only)
‰
Place the UV beads, rinsed-out vial, Gore-Tex® glove(s), and magnets
into the envelope(s) provided and give it, the UV light, and the box of
goggles to the librarian so that they can be returned to the branch at Solon
by interlibrary mail. (library kits only)
‰
Activities To Do Once You Get Home
Leave a message for Kat Wollyung with attendance information and other
comments at [email protected]
National Chemistry Week 2004 - Cleveland Section
4 When Complete
‰
6
Required Supplies
Demonstrator’s Guide
Supplies Required for Demonstration
Items for Demonstrator to Provide (or to request in advance from the librarian)
2 basins, small-med. buckets, or other very wide-mouthed containers (for use in Expt 1
and for liquid waste collection thereafter)
1 large garbage bag for solid waste collection
Approximately 2 gallons of Water (Note: It may be difficult to transport water from
library restrooms or fountains with low spigots, so don’t plan to use this method to
obtain water unless you have investigated the water availability at your site.)
1 roll paper towels, if none at site
Newspaper for covering 7 long tables with a few layers of paper (if none at library)
Scissors (for cutting tips off pipettes and cutting the 3M casting material) (Expt 5 and 7)
Measuring spoons (Tablespoon, teaspoon, and ½ teaspoon )(Expt 2 and 6)
One-quarter cup measuring cup (for measuring water) (Expt 8 and 9)
A metal spoon (for crushing Tums® tablets and vitamins) ( Expt 7 and 9)
Extension cord (if none available at library)(Expt 4 and 9)
Optional for Expt.7: Calcium fortified orange juice and a clear, disposable, plastic cup
Notice: If you will be performing multiple demonstrations on the same day, you will need to
sanitize the goggles between demonstrations. You will also need:
Small quantity of household bleach
Wash bin or bucket
Rags, old towels, or cotton paper towels for drying (soft so as not to scratch the goggles)
Teachers: You may need to provide your own UV light(s)
Items Provided in Each Demonstration Kit:
General:
1 box containing kit contents
30 copies Celebrating Chemistry newspapers (if available from ACS)
30 copies each of ‘Book List’ and other take home materials
10 copies of ChemMatters magazine (if available from ACS) (library kits only)
1 envelope for returning supplies (addressed to Solon) (library kits only)
1 UV (black) light (addressed to Solon) (library kits only)
1 box of goggles (30 child & 2 adult size, addressed to Solon Library) (library kits only)
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Required Supplies
Demonstrator’s Guide
Experiment 1: High Tech Fabrics – Fabric Breathability
1-3 Gore-tex® membrane gloves (demo gloves, each inside a zip-loc bag,
courtesy of W. L. Gore and Associates, Inc.)
3-5 “regular” polyethylene (food service-type) gloves as a control
PurellTM hand sanitizer
Experiment 2: Sunscreen
3 3oz white plastic bathroom cups
3 UV color-change beads (white beads that turn purple when exposed to UV light)
½ clear transparency sheet with 3 labeled circles—SPF 0; SPF 20, SPF 45
one sample each of two different sunscreens with different SPF values (LipSmackers®
sunscreen courtesy of Bonne Bell, Inc.)
cotton swab
UV light
Experiment 3: Soothing the Pain – Hot and Cold Compresses
14 zipper-top sandwich bags, empty, unmarked
7 zipper-top sandwich bags, empty, marked “C”
7 zipper-top sandwich bags, empty, marked “H”, wrapped in plastic wrap, which have
been coated with a UV-visible lotion that will become part of the next demo
7 small paper cups marked “A”
7 small paper cups marked “B”
7 small paper cups marked “C”
1 zipper-top sandwich bag marked “CaCl2”, containing 3 ½ teaspoons calcium chloride
1 zipper-top sandwich bag marked “citric”, containing 3 ½ teaspoons citric acid crystals
1 zipper-top sandwich bag marked “soda”, containing 3 ½ teaspoons baking soda
Experiment 4: Watch Out for Germs! – Glow Germs and UV Light
ultraviolet light
Experiment 5: Casting a Broken Finger
7 plastic bags containing plaster of Paris
7 paper cups
7 stirring sticks
7 plastic squares with attached cheesecloth
1 empty vial for 15ml measure
1 clear plastic cocktail-style cup (to use as a container for water)
1 paper towel
1 intact pair of rubber gloves and 6 rubber glove fingers
1 plastic bag containing urethane cast material (3M Scotchcast plus®) (DO NOT OPEN
UNTIL READY TO DO DEMO WITH STUDENTS) (courtesy of 3M Company.)
1 paper strip cutting guide
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Required Supplies
Demonstrator’s Guide
Experiment 6: Finding the Iron in Cereal
7 zipper-top sandwich bags containing about ¼ cup Total® cereal
7 clear plastic cocktail-style cups marked water
7 plastic spoons
7 magnets
7 sandwich bags (not zipper-top), empty
7 small pieces of white paper (1/4 sheets or smaller)
7 small plastic cups
Experiment 7: Detection of Calcium in Milk
1 vial marked “Alginate” filled with the green sodium alginate solution in a baggie
1 zipper-top double bag labeled “Tums” with 6 Tums® tablets
7 plastic spoons
7 clear plastic cocktail-style cups (9 oz.)
1 large plastic cup (12 – 16 oz.)
1 plastic bottle labeled “vinegar” containing about 60 ml white vinegar
1 beral pipet
Experiment 8: Testing for Carbohydrates - Starch
7 snack-sized bags containing ½ teaspoon potato flakes
7 snack-sized bags containing ½ teaspoon sugar
14 clear plastic cocktail-style cups (7 marked “pot” and 7 marked “sug”)
14 stirring sticks
2 sealed pipettes containing iodine solution
Experiment 9: Vitamins! Vitamins!
1 snack-sized bag containing a 500 mg chewable vitamin C tablet (round, orange)
1 clear plastic cocktail-style cup marked “vit C”
7 small paper cups
7 pipettes
1 snack-sized bag containing a multivitamin tablet (oblong, yellowish-brown)
1 clear plastic cocktail-style cup marked “MV” (for multivitamin)
2 stirring sticks
ultraviolet light
potato flake “solution” containing iodine and stirring stick (from Experiment #8)
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Experimental Setup
Demonstrator’s Guide
Activities to Do On-site Prior to Demonstration
General:
¾ Refer to page 5 for items to verify room setup (6 student tables with 5 chairs each, one
demonstrator table, all covered with newspaper, each with paper towels, etc. & obtain any
supplies requested from librarian)
Experiment 1: High Tech Fabrics – Fabric Breathability
¾ Distribute the Gore-tex® glove(s) and regular polyethylene gloves among the student tables,
keeping one regular polyethylene glove for the demonstrator table.
¾ Fill your two buckets/basins about half full with water and place them in an area where 3
children can stand/sit around each bucket and each dunk their hands. They will be removing
their wet hands from the buckets/basins at some time, so set up this experiment where they
will not get other items on your demo table (or the floor) too wet. If your table is full of
demonstration items, you may choose to do this demo over many layers of newspaper on an
open area of floor towards the center of the room.
¾ Place a number of paper towels in the area of the buckets for the children to dry their hands
after the experiment.
¾ Place the Purell on to demonstrator’s table.
Experiment 2: Sunscreen
¾ Place 3 white bathroom cups, transparency, cotton swab, and sunscreens on the front table.
¾ Place the three UV beads nearby.
¾ Set the UV lamp nearby. Connect with an extension cord if you wish to reach
all the
tables.
Experiment 3: Soothing the Pain – Hot and Cold Compresses
¾ Place 2 tablespoons of room-temperature water in each of the unmarked zipper-top sandwich
bags and seal.
¾ Distribute the CaCl2 evenly into the 7 cups marked “A” (approx. ½ teaspoon in each).
¾ Distribute the baking soda evenly into the 7 cups marked “B” (approx. ½ teaspoon in each).
¾ Distribute the citric acid evenly into the 7 cups marked “C” (approx. ½ teaspoon in each).
¾ Place 2 zipper-top bags containing water, 1 zipper-top bag marked “C”, 1 cup marked “A”, 1
cup marked “B”, and 1 cup marked “C” at each table.
¾ Trying not to handle the bags very much, place 1 zipper-top bag marked “H” (coated with a
UV-visible lotion that will be part of the next demo) onto each table. You don’t want to
wipe off the lotion. Put it off to the side so that the students will not touch it (or touch it
National Chemistry Week 2004 - Cleveland Section
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Experimental Setup
Demonstrator’s Guide
much) before this particular demo. Although not absolutely necessary, wash your hands
before setting up the next experiments so that you do not transfer lotion onto the other demo
items.
Experiment 4: Watch Out for Germs! – Glow Germs and UV Light
¾ Note: You will be using the ultraviolet light (with extension cord if desired) again for this
demo. It was originally used in Experiment 2.
Experiment 5: Casting a Broken Finger
¾ Empty the bags of plaster of Paris into the paper cups and place one cup on each table.
¾ Cut 6 strips from the paper towels which are wide enough to wrap around a child’s finger.
¾ Distribute the plastic squares with cheesecloth, paper towel strips, glove fingers, and sticks to
each table.
¾ Fill the cocktail-style cup (about 3/4 -full) and put it on demonstrator’s table.
¾ Lay the empty “Expt. 5” gallon-size zipper-top bag on the demonstrator’s table to use as a
work surface. Place the intact pair of polyethylene “rubber” gloves, the bag of urethane cast
material, your scissors/shears, the paper-strip cutting guide and the 15ml measure on the
work surface. NOTE: Do not prematurely open the bag of 3M Scotchcast material! It will
start to harden upon exposure to the moisture in the air.
Experiment 6: Finding the Iron in Cereal
¾ Fill the 7 clear plastic cocktail-style cups with approximately ¼ cup room-temperature or
warm (not hot) water. (To estimate, water should be just less than 1” deep in cup.)
¾ Fill the 7 small cups about one-half (1/2) full with water (temperature does not matter).
¾ Place 1 bag of cereal, 1 clear plastic cup with water, 1 plastic spoon, 1 magnet, 1 empty
sandwich bag, 1 piece of white paper, and 1 small cup with water at each table.
Experiment 7: Detection of Calcium in Milk
¾ Place the large plastic cup, vinegar, 7 clear plastic cocktail-style cups, baggie of Tums®,
metal spoon, beral pipet, plastic spoons, and the vial of alginate solution on your front table.
Experiment 8: Testing for Carbohydrates - Starch
¾ Fill the 14 clear plastic cocktail-style cups with ¼ cup of room-temperature or warm water.
(To estimate, water should be just less than 1” deep in cup.)
¾ Place 1 bag of potato flakes, 1 bag of sugar, 2 stirring sticks, and 1 of each clear plastic cup
on each table.
¾ Place the sealed pipettes containing iodine solution and scissors on demonstrator’s table.
National Chemistry Week 2004 - Cleveland Section
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Experimental Setup
Demonstrator’s Guide
Experiment 9: Vitamins! Vitamins!
¾ Fill the clear plastic cocktail-style cup marked “vit C” with 1/2 cup of room-temperature or
warm water.
¾ Fill the clear plastic cocktail-style cup marked “MV” with 2 tablespoons water.
¾ Place 1 pipette on the demonstrator’s and each student table.
¾ Place both clear plastic cocktail-style cups containing water, snack bag containing vitamin C
tablet, 2 stirring sticks, 7 small paper cups, and snack bag containing multivitamin tablet on
demonstrator’s table.
¾ Note that the ultraviolet light, extension cord, and sturdy metal spoon will have been used in
earlier experiments so they may not necessarily be set out with the rest of the supplies for
this demo.
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Opening Session
Demonstrator’s Guide
Opening Discussion
Introductions
Do the following:
¾ Introduce yourself as a chemist (or state your interests in chemistry), and introduce the
American Chemical Society as the largest organization in the world devoted to a single
profession.
¾ Introduce National Chemistry Week - what it is and why we do it. (Hint: it is a nationwide
event put on by volunteers like you to let non-chemists know about chemistry and how it has
improved our everyday life.)
What is Chemistry and Chemicals?
Do the following:
¾ Explain that chemistry is the study of everything around them.
¾ Ask volunteers to name some chemicals. Then ask more volunteers to name something that
isn't a chemical.
Remember: everything around us is a “chemical”.
Be very careful in correcting the students. Encourage their participation
while explaining that anything they name really is a chemical.
What Do Chemists Do?
¾ Ask the participants to tell you what a chemist does, what a chemist looks like.
¾ Tell them BRIEFLY and in simple terms what you do as a chemist.
¾ Note: This should last no more than 1 minute. Remember to leave the physical chemistry
lecture and the “big” chemistry words at home!
¾ Tell them that chemists use their knowledge to answer questions about the world around
them. This is very exciting, as they will soon see.
Introduce the Items on the Tables
Do the following:
¾ Tell them not to touch anything until told to do so. Remind them never to taste or smell
anything, as if they were in a laboratory.
Note: Some of the items in the demonstration are actual food items. Remind students throughout
the demonstration not to eat or drink anything!
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Opening Session
Demonstrator’s Guide
Introduce the Items on the Tables and Distribute Goggles
Do the following:
¾ Tell the students that various items have been gathered for them on their table.
¾ Tell them not to touch anything until instructed to do so.
¾
Most of the items can be found around the house. Remind them never to taste or smell
anything, as if they were in a laboratory!
¾ Tell the students that even though most of our items are relatively harmless today, we will
still be good chemists and take the safety precaution of protecting our eyes.
¾ Put on a pair of the adult-sized goggles. If you have an assistant, ask them to do the same.
¾ Distribute the goggles (if you haven’t already done so) and help the students put them on.
Adjust the straps as necessary. (Note: These goggles are sanitized each year and prior to
each demonstration.)
Introduce Today’s Presentation:
The Chemistry of Health and Wellness
Tell the students the following:
This year’s theme for National Chemistry Week is “The Chemistry of Health and Wellness”.
¾ When we hear the word “chemical” in the news, it is often in a story about a ‘bad’ or
‘dangerous’ chemical spill, or how a chemical has been found to be harmful to our health.
But this isn’t always the case! Chemistry can be good for us too!
¾ Have the students try to name a few helpful ‘chemicals’. [Medicines and vitamins, gasoline
and oil for cars, fertilizers, cleansers/detergents.]
¾ Tell the students that we will be using the scientific method to guide us in our investigation
of various items associated with our health. We will make observations, form a hypothesis,
use experiments to test our hypothesis, and then evaluate the results of the experiment to
accept or reject the hypothesis.
¾ We will learn some cool facts about Health and Wellness along with our story characters,
Millie and Amadeus. Millie’s name refers to the prefix ‘milli’ m.i.l.l.i. (spell it out) as in
milliliter and milligram which are important units of measurement in chemistry. Amadeus
refers to a famous scientist Amadeus Avogadro who helped us learn another important
chemical unit, the mole, which is a word used for the very large number 6.023 x 1023 similar
to the way we use the word ‘dozen’ to represent the number 12.
¾ We’ll follow our two characters, Millie and Amadeus, on their hiking adventure – or
misadventure, as it turns out! So let’s get started!
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Experiment 1
Demonstrator’s Guide
Experiment 1: High Tech Fabrics – Fabric Breathability
Experiment Purpose & General Methodology
•
The students will be informed of the directional wicking of high tech fabrics.
•
Each table will have one student participant and the experiment should take about 8 minutes.
Introduce the Experiment
Tell the students the following:
¾ Today’s hikers or sports enthusiasts can venture out wearing high-tech or engineered
clothing, thanks to the work of chemists and chemical engineers. The goal of high-tech clothing
is to keep you warm and dry in winter, and cool and dry in summer. Millie and Amadeus know
this, and wore their best hiking boots for their trip.
¾ Through our next experiment, we will learn about the directional (or one-way) wicking of
high tech fabrics, such as those in the boots being worn by our characters. It was too expensive
to bring Gore-Tex® boots for our experiment, but we were able to get gloves.
Perform Experiment with the Students
Do the following:
¾ Have one child from each table bring their table’s glove to the front of the room.
¾ If available, have children who will be using Gore-Tex® gloves clean their hand with
PurellTM or bacterial soap to ensure the cleanliness of our reusable Gore-Tex®gloves.
(Note: These gloves will be collected after the demonstration and cleaned and sanitized by the
Cleveland NCW committee for possible future demonstration programs. At this time (2004
program), the gloves are NEW and clean.)
¾ Using a “regular” polyethylene glove, the demonstrator should lead and instruct the students
in the following steps:
a.) position the students around the buckets (3 children for one bucket, and 3 children plus
the demonstrator for the second bucket),
b.) wet one hand and gently shake off most of the water,
c.) put the glove on your damp hand and hold the glove closed around the wrist with your
other hand,
d.) place the gloved hand back in the bucket; do not let water come over the top of the glove,
e.) move your fingers gently for 2 to 3 minutes to create heat, simulating outdoor activity,
f.) while waiting to 2 – 3 minutes, tell/ask the students…
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Experiment 1
Demonstrator’s Guide
¾ Why is it so important to stay dry? (a) to keep you comfortable, (b) to keep you smelling
nice (because when you sweat, bacteria break down the sweat and cause an odor), and (c) most
importantly, to keep you from freezing. Our bodies lose heat five times faster in wet clothing!
¾ Picture the hiker who is climbing in the mountains. During the day it can be warm and
comfortable, but at night, or higher up in the mountains, it can quickly get very cold. If a hiker’s
clothing is wet with sweat or water, he/she can rapidly lose heat, and possibly freeze.
¾ Luckily, Millie and Amadeus are wearing boots made of a neat fabric that keeps them dry by
transporting body sweat away from the skin, plus it keeps water off of them when they step
across and through small streams. This fabric is called Gore-Tex® and it’s the world’s first
waterproof and breathable fabric. It was invented when chemical engineer, Bob Gore, quickly
stretched some Teflon or PTFE (polytetrafluoroethylene) which was a synthetic, or man-made
polymer, or type of plastic, invented by a chemist at DuPont. It is used in boots, gloves, and
coats.
¾ Remove your hand from the bucket, remove your polyethylene glove, and show the students
that your hand is still wet.
¾ Have the students remove their hands from the buckets and remove the gloves. (Do this over
some paper towels so as not to get the table and floor wet.)
¾ Ask about others’ hands. Are they wet? Are they cold or warm?
¾ The hands in the Gore-Tex® gloves should/will be completely dry! (IF NOT, have only the
student(s) with the Gore-Tex® glove(s) put their hands back in the bucket/basin and continue
with the conclusion and additional information sections below to give the gloves more time to
work.)
Conclusions
¾ Gore-Tex® fabric is breathable. It keeps outside water from touching you, like a raincoat.
In addition, it allows the water or sweat right next to your skin to escape to the outside.
¾ The water on your skin is warmed by your body heat and forms very tiny droplets or watervapor (a gas) which moves through the small holes or channels in the fabric. These same small
channels are too small for outside rain water, with larger droplets, to get in.
Additional Information If Needed: Technical Background
• The water inside the glove was warm, due to body heat plus movement (remember you
moved your fingers and made the water warm). Some water near your hand was in the vapor
form (whenever there is water, there is some water vapor above it and they are in equilibrium).
(You are aware of this when you notice that water in a glass evaporates). The temperature
difference (between the warm water in the glove and the cold water in the bucket) created a
driving force that allowed water vapor to move through the glove and be whisked away. This
disturbed the equilibrium between the liquid water and the water vapor inside the glove; there
National Chemistry Week 2004 - Cleveland Section
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Experiment 1
Demonstrator’s Guide
was less vapor, so to compensate, more was formed. It, too, was whisked away. The cycle
continued until your hand was dry!
• Note that water does not get back in the glove. Liquid water has a high surface tension molecules of water are attracted to each other through hydrogen bonding. This “sticky” liquid
form of water thus cannot get into the glove.
• True breathability is different from ventilation, which is attempted by cutting vents or holes
in fabric. Even fabrics which are vented (like a plastic raincoat with vents in the armpit area or
sides) may not be “breathable”. Moisture can still build up. True breathability is created by the
use of certain materials, as well as the small diameter of their fibers, and the way that they are
woven or engineered using non-weaving techniques (so that the right-sized channels or pores are
created for water vapor movement).
• Millie and Amadeus own Gore-Tex® coats, boots, and gloves to keep them dry in the rain
and snow. When running around in the winter, they can make snowballs and igloos, and their
hands inside stay perfectly dry as sweat is whisked away.
• Gore-Tex® fabric was used in spacesuits worn by astronauts on the first space shuttle,
Columbia. It was worn by a team of explorers in Antarctica in 1990, and is credited with saving
the life of one of them. You may have a coat or gloves made of this fabric, or you may use it if
you use Glide® dental floss or Elixir® guitar strings. (www.gore.com)
• Let’s talk about underwear and socks. You know how cold you get when you’re wearing a
wet swimming suit or you step in a puddle and your socks are wet. You want to keep the fabric
right next to your skin as dry as possible to stay warm and comfortable.
• We do not need to have underwear or socks that are also waterproof, because your coat and
shoes can do that. But we do want them to keep you dry. In addition to Gore-Tex® , there are
other fabrics like CoolMax ®, a polyester material (which is synthetic or man-made), that can
do this (http://www.fabriclink.com/producers.html). Some natural fibers, like wool and alpaca,
are also quick drying. (Check out http://users.rcn.com/icebike/Articles/fabrics.htm for
explanation of the breathability and waterproof properties of various fabrics.)
• Our bodies lose heat by direct contact (with water, for example, by conduction), by air
movement (when wind is blowing on us, for example, by convection), infrared energy emission
(radiation), evaporative cooling (when our liquid sweat becomes a gas, by evaporation), and
through respiration (when we exhale heated air out of our lungs).
• When you are wet, you lose extra heat through conduction and evaporation, and wind chill
can aggravate the situation. Water can conduct heat 25 to 30 times greater than air. A person
who falls in cold water can lose heat 100 times faster than in air (considering that the mass of
water next to your skin is huge compared to the mass of air in the same volume).
(http://www.umm.edu/outdoor/hypothermia.htm),
(http://www.newton.dep.anl.gov/askasci/phy00/phy00690.htm)
National Chemistry Week 2004 - Cleveland Section
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Experiment 2
Demonstrator’s Guide
Experiment 2: Sunscreen
Experiment Purpose & General Methodology
• The students will learn about sunscreens and SPF ratings.
• This experiment will be done per table and will take approximately 5 minutes to complete.
Introduce the Experiment
Tell the students the following:
¾ As Millie and Amadeus set out for their hike on a sunny summer day, they realize that they
need to protect themselves from the elements. Ask students what they do to protect themselves
from the elements when they go hiking. Students will probably respond with hat, coat, bug
spray, first aid kit and perhaps SUNSCREEN.
¾ Why do we need sunscreen? Protection from Ultraviolet radiation that can cause burns,
premature aging and cancer. As summer approaches, our hemisphere tilts toward the sun, days
become longer, and the sun’s rays become more intense.
Perform Experiment with the Students and Discuss How Sunscreens Work
Do the following:
¾ Show the students the three UV beads held in your hand. Explain that these beads absorb
UV light and change color. Place one UV bead in each cup.
¾ Ask for two volunteers. Each student will rub on one of the sunscreens onto the circle on the
transparency labeled with the SPF value of that sample.
(One is applied like lipstick, the
other is applied with the cotton swab. The entire area of the circle is to be covered. While they
are covering the circles inform the students…
ƒ To be sure you are protecting yourself from damaging rays, sunscreen should be one part
of an overall strategy to keep your skin healthy. In Australia, the country that has the highest
rates of skin cancer in the world, people are urged to "slip, slop, slap". That is, slip on a shirt,
slop on sunscreen, and slap on a hat when you need to spend time in the sun. Staying out of
the sun during peak hours (10 a.m. to 4 p.m.) is also recommended.
ƒ Sunscreen lotions absorb certain wavelengths of light before they reach the body. UV light
with a wavelength range of 400–320 nm and 320–290 nm are referred to as UVA light and
UVB light, respectively. Different wavelengths have different energy. Depending on the type
and amount of sunscreen present, only a percentage of UV light will actually reach your skin.
¾ Ask the students if they know what SPF on the sunscreen labels means? (Sun protection
factor). You will discuss this more in a moment.
¾ Position the cups so that each cup is below the circle.
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Experiment 2
Demonstrator’s Guide
¾ Hold the UV lamp over the beads long enough for their colors to change (typically <10 sec).
¾ Pass the three cups around to each table so they may examine them.
Conclusions
¾ Sunscreen lotions absorb certain wavelengths of light before they reach the body. Depending
on the type and amount of sunscreen present, only a percentage of UV light will actually reach
your skin. The sun protection factor (SPF) on sunscreen bottles is related to this percentage.
Very simply, if you can prevent half as much light from hitting your body, you can stay in the
sun twice as long (SPF 2). If only 3% of the light gets through, then you can stay out 33 times
longer (SPF 33). The actual SPF for a particular lotion is more complicated and is determined
experimentally by measuring actual burn rates.
¾ Ask them again what to do to protect themselves: Slip, Slop and Slap. Do not become
deluded! The best course of action is still to avoid sun exposure during peak hours (10 a.m.–4
p.m.). If you must be out, wear a hat. Remember, a backward baseball cap might look really
cool, but it does not protect your face, forehead, and ears. Your best bet is a hat with a large
brim. My unofficial observation is that the goofiness and the sun protection of a hat are directly
proportional, so lather up with sunscreen, wear your silliest hat, and get out there!
Technical Information
• Without the sun, there would be no life on Earth. It keeps our planet warm. Plants need the
sun's radiant energy for photosynthesis. People need small amounts of exposure to activate
vitamin D in their bodies, a substance important to bone-building and other biological processes.
• You can have too much of a good thing though. Too much sun can cause sunburn. Over time,
too much sun can age the skin, making it leathery and inelastic. Researchers have also noticed a
strong correlation between too much sun when you are young and skin cancer when you are older.
• Sunlight is made of many different kinds of light. These kinds of light have different energies
and their properties are a result of these energies. Not all kinds of light cause sunburn. Only
ultraviolet (UV) light damages skin.
• Light energy is measured in wavelengths (γ); the smaller the wavelength, the greater the
energy. UV light is usually broken down into three subtypes:
UVA, 320-400 nm wavelength
UVB, 290-320 nm wavelength
UVC, 200-290 nm wavelength
• UVC light will do the most damage to your skin. Fortunately, this kind of light is completely
absorbed by the atmosphere. Too much UVB light is responsible for sunburns. UVA light can
damage your eyes over time. UVB and UVA go right through the air and clouds, which is why
you can still get sunburned on an overcast day.
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Experiment 2
Demonstrator’s Guide
• Scientists aren't sure which type of UV light (UVA or UVB) causes the increased likelihood
of skin cancer.
• Full-spectrum sunblock lotions are popular these days because—although UVB light causes
sunburns—scientists aren’t sure whether UVA, UVB, or some combination of the two is
responsible for causing skin cancer. Full-spectrum lotions typically absorb a wide range of
wavelengths, including UVA and UVB. To achieve broad coverage, the lotions use multiple
sunscreens that are selected on the basis of either a favorable property (waterproof,
hypoallergenic) or a wavelength range they absorb.
• Sunscreens work by absorbing some of the UV light before it reaches your skin. Compounds
such as cinnimate, oxybenzone, salicylates, and dibenzoylmethanes absorb UV light at different
wavelengths, so many manufacturers put more than one UV-absorbing compound in their spray
or lotion to give better protection from the sun. Most sunscreens block UVB rays.
•
These five active ingredients are good examples of typical sunscreen compounds.
Octyl salicylate is one of a class of sunscreen
compounds called salicylates. They absorb UVB
light over the full range but are not particularly
effective sunscreens because they have low
absorptivity. Their saving grace is that they are
stable, hypoallergenic, and waterproof.
Oxybenzone absorbs both UVA and UVB light
but is generally considered a UVA blocker.
Octyl methoxycinnamate is part of a class of
sunscreen compounds called cinnamates that
absorb strongly in the UVB range but are not
waterproof. In this formulation, and in many
others, it is used in combination with waterproof
ingredients such as octyl salicylate (above).
Octylcrylene is a relatively new sunscreen that provides superior coverage in the UVB range.
Titanium dioxide (TiO2) does not absorb UV light at all, but rather blocks light from reaching
your skin by reflecting or scattering it. It is sometimes referred to as a “nonchemical” sunblock
(as a chemical enthusiast, you should find this silly because, of course, it’s a chemical). TiO2 is
different from the compounds above because the skin does not absorb it; it works by physically
blocking the light. TiO2 sunscreens are extremely effective and hypoallergenic. It might surprise
you that another consumer product also uses TiO2—white paint! TiO2 sunblocks were not widely
used in the past because they stayed white when applied (remember the white noses?). The
particle size of new “micronized” TiO2 formulations is so small that TiO2 sunblock is invisible
on skin.
National Chemistry Week 2004 - Cleveland Section
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Experiment 3
Demonstrator’s Guide
Experiment 3: Soothing the Pain – Hot and Cold Packs
Experiment Purpose & General Methodology
• The students will obtain an understanding of how germs spread and ways to control infection
• This experiment will be done by each table and should take <5 minutes to complete.
Introduce the Experiment
Tell the students the following:
¾ Millie and Amadeus are having a marvelous hike on a sunny day. Millie loves crossing the
streams in her high-tech boots. Sometimes she tramps right trough smaller streams since she
knows her feet will stay comfortably dry. Unfortunately, even small streams can have slippery
rocks, and when crossing one stream she slips and falls, hurting her finger and wrist. Too bad!
But accidents happen, and Amadeus is always well prepared for his hiking trips, and gets out his
first aid kit to help.
¾ Ask the students: What is one of the first things that you might do when you have a minor
injury like a sprained ankle or other bruise? (Put something cold like ice on it.)
¾ But what do you do if you are hiking on a trail or if you are playing at a ball field and there
isn’t any ice around? Chemistry provides the answer!
¾ Has anyone ever seen or used one of those cold packs that you can keep in a first aid kit until
it is needed? One of the more common types feels like a plastic bag full of pellets. The pellets
are usually a type of salt, called ammonium nitrate, and there is an inner pouch that contains
water. To activate the cold pack, it must be squeezed so that the inner pouch breaks and releases
the water. As the ammonium nitrate pellets dissolve in the water, they absorb heat from their
surroundings (the water… and your skin) and the cold pack feels cold. And hopefully, your
bruise feels better!
¾ A chemical reaction or a physical process that absorbs energy from its surroundings is called
endothermic.
¾ Tell the students that we will create an endothermic reaction to make our own cold pack.
Perform Experiment Simultaneously with the Students
Part I – Endothermic Reaction/Cold Pack
Do the following, leading the students:
¾ Have each table locate one of the zippered bags containing water and have the students feel
and describe the temperature of the water – it should be room-temperature or lukewarm.
Note: Our fingers and palms of our hands are not very good at sensing temperature. The best
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Experiment 3
Demonstrator’s Guide
way to feel the temperature would be to hold the bag against the inside of the wrist or the back of
the hand.
¾ Have one student carefully open the bag and hold it open.
¾ Have a second student locate the cup marked “C” (containing citric acid) and pour the
contents into the water in the open bag. Agitate gently (remember, the bag is open at this point!)
to dissolve and disperse the citric acid.
¾ Warn the students not to get startled during the next step. Hold the bag steady. Have a third
student locate the cup marked “B” (containing baking soda) and pour the contents into the citric
acid solution in the open bag. An immediate reaction, bubbling (due to the formation of a gas,
CO2) will occur!
¾ Keep the reaction bag open (unsealed) until the bubbling stops, then carefully seal the bag
and place it in the empty bag marked “C” to help guard against leaks. Have the students pass the
bag around the table so that everyone can feel that the water in the bag has gotten cooler!
Note: Use the back of the hand or inside of the wrist like before.
Conclusions for Endothermic Reaction/Cold Pack
Tell the students the following:
¾ The chemical reaction between citric acid and baking soda is an acid-base chemical reaction.
Carbon dioxide is the gas that is given off.
¾ We know that the reaction is endothermic (it uses up heat to occur) because we felt the
reaction solution get colder. The reaction absorbs heat from its surroundings (the water and our
skin), so it feels cold.
Introduction for Part II – Hot Pack
Tell the students the following:
¾ Many times, after the initial pain and swelling of an injury subsides, a doctor tells you to put
heat on an injury to help it heal.
¾ How do you put heat on an injury? You could use an electric heating pad or a hot water
bottle, but those require access to electricity or hot water. Again, chemistry can provide another
solution in the form of portable heating packs!
¾ There are various kinds of chemical heating packs, ranging from supersaturated solutions of
a salt called sodium acetate that give off heat as the salt crystallizes, to the chemical reaction of
iron rusting, to pellets of calcium chloride that give off heat as they dissolve in water.
¾ A chemical reaction or a physical process that gives off energy to its surroundings is called
exothermic.
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Experiment 3
Demonstrator’s Guide
¾ Later on, when Millie gets home, she may want to use a heating pack on her wrist to help the
pain subside, so she might buy one at a pharmacy. While we cannot make one here as good as
the ones we can buy at the store, we will use other items to create an exothermic reaction to
make our own hot pack.
Part II – Exothermic Reaction/Hot Pack
Do the following, leading the students:
¾ Locate the other zippered bag containing water and have the students feel and describe the
temperature of the water – it should be room-temperature or lukewarm.
¾ As in the previous experiment, have a student carefully open the bag.
¾ Have a second student locate the cup marked “A” (containing calcium chloride) and pour the
contents into the water in the open bag.
¾ Carefully seal the bag and place it in the empty bag marked “H” to help guard against leaks.
Gently agitate the bag to disperse the calcium chloride pellets.
¾ Have the students pass the bag around the table so that everyone can feel that the water in the
bag has gotten warmer! Note: The calcium chloride pellets can get very warm! Do not let
students squeeze the pellets that have not fully dissolved.
Conclusions for Endothermic Reaction/Cold Pack
Tell the students the following:
¾ In our hot pack, the calcium chloride gives off heat as it dissolves in the water. This is a
physical process, not a chemical reaction.
¾ We know that the process is exothermic (it gives off heat when it occurs) because we felt the
reaction solution get warmer. The process gives off heat to its surroundings (the water and our
skin), so it feels warm.
Additional Information If Needed: Technical Background
• The chemical reaction for our cold pack is:
H3C6H5O7 (aq) + 3 NaHCO3 (s) Æ 3 CO2 (g) + 3 H2O (l) + NaC6H5O7 (aq)
• The dissolution equation of our hot pack is:
CaCl2 (s) Æ Ca2+ (aq) + 2 Cl- (aq)
Each gram of CaCl2 that dissolves releases 160 cal into the water.
National Chemistry Week 2004 - Cleveland Section
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Experiment 4
Demonstrator’s Guide
Experiment 4: Watch Out for Germs! – Glow Germs and UV Light
Experiment Purpose & General Methodology
• The students will obtain an understanding of how germs spread and ways to control infection
• This experiment will be done by each student and should take <5 minutes to complete.
Introduce the Experiment
Tell the students the following:
¾ Although Millie’s wrist is feeling better, they both know that her finger is injured too much
for them to help on their own so they decide to go to the doctor’s office.
¾ When Millie and Amadeus get to the doctor’s office, they notice that the doctor is wearing
rubber gloves, so they ask the doctor why he is wearing gloves.
¾ Ask the students if they know why doctors, nurses, dentists, etc. wear rubber gloves.
¾ We can’t see germs, but they can make us sick, so we must always be careful to limit our
exposure to germs.
¾ What are some ways that we might become exposed to germs? (sneezing, coughing, shaking
hands, sharing a drink with someone else, …)
¾ What are some things we should do to protect ourselves? (wash our hands often, eat right,
…)
Perform the Experiment Simultaneously with the Students
Do the following, leading the students:
¾ Tell the students: We know that we cannot see germs, but what if we used a fluorescent
material to represent the germs we might come in contact with in our lives. Fluorescent materials
glow under an ultraviolet light (sometimes called a UV or black light), so we’d be able to see our
“imitation germs” only under a UV light.
¾ Ask the students if any of them think that they have come in contact with any germs lately.
¾ Tell the students that there may have been some fluorescent “imitation germs” in our
program today and that we can check to see if anyone came in contact with those “germs” by
looking at their hands under ultraviolet light.
¾ Turn on the ultraviolet light and turn down the room lights (if possible) and look at the
students’ hands under the light. If you did not bring an extension cord to reach all of the tables,
you may want to bring the students up to the UV light by tables.
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Experiment 4
Demonstrator’s Guide
¾ If you have an extension cord that reaches at least one student table, ask them if they can
figure out where our germs came from. (The bag marked ‘H” where we made our hot-pack, but
they should not necessarily be able to guess this!)
¾ Note: Certain materials in shirts, teeth, and bruises on skin can also absorb and reflect UVlight.
Conclusions
Tell the students the following:
¾ Originally our “imitation germs” were only on ONE item on the table – the bag marked ‘H’
used in our last experiment. Now they are in many places since we easily spread them around!
¾ Germs can be anywhere. We must be careful. We should wash our hands frequently and
avoid putting things like pencils or toys in our mouths.
¾ Remind the students some ways that we might become exposed to germs. (sneezing,
coughing, shaking hands, sharing a drink with someone else, …)
Additional Information If Needed: Technical Background
• One type of ‘germ’ is bacteria. Certain types of bacteria can live on a wet surface for a long
time. A wet sponge spread these types of bacteria when we use it to wipe off a surface. This is
an easy way to quickly spread bacteria. If we are cutting foods on a cutting board, for example,
we should make sure the board is clean and dry. A board that is wet with a bacteria filled sponge
can transfer bacteria to our food! Yuck! Fortunately, we often use soap with our sponges which
can easily wash away the bacteria. Some soaps come with bacterial fighting agent to kill any
that may have been left behind. Also, many types of bacteria die after being exposed to air for a
short amount of time. So, using a cleaned and dried cutting board can lower the chances of
spreading bacteria. Rinsing your sponge with soap and water after each use is a good idea too.
• Doctors and nurses change gloves and/or wash their hands every time they see a new patient
to help prevent the spread of germs between the patients they see.
•
To find out more on preventing the spread of germs, visit these web sites:
http://www.cdc.gov/flu/school/
http://www.elmbridge.gov.uk/services/environment/germspread.htm
http://www.cdc.gov/germstopper/home_work_school.htm
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Experiment 5
Demonstrator’s Guide
Experiment 5: Casting a Broken Finger
Experiment Purpose & General Methodology
• Students at each table will make a piece of cast material which demonstrates the old broken
bone casting technology using plaster of Paris and cheesecloth.
• One student at each table will then have a cast made of one of their fingers based on modern,
quick-setting casting material.
Introduce the Experiment
Tell the students the following:
¾ After the doctor looked at Millie’s finger and took some X-rays, it was determined that she
had broken her finger. The doctor has choices of materials to choose from to make the cast.
Some are more old-fashioned and some are made of modern high-tech material.
¾
We’ll investigate one old and one new technology for putting a cast on Millie’s finger.
Perform Experiment Simultaneously with the Students
Do the following, leading the students:
¾ Have the students locate the cup of plaster of Paris, the cheesecloth, and the stirring stick.
¾ Using the 15 ml measure, put 15 ml of water into each cup of plaster and have the students
take turns stirring the plaster.
¾ Have a student fold back all but one of the cheesecloth strips from the plastic piece.
¾ Using the stirring sticks, have a student coat the first cheesecloth strip with a thin layer of
plaster. The neighboring student(s) can help hold the cheesecloth while the student spreads the
plaster. They can coat just the center area of the cloth; they do not need to coat it perfectly.
¾ Fold the next strip of cheesecloth over the coated one, add another layer of plaster, and repeat
until finished, leaving the top layer of cheesecloth uncoated. Make sure the layers are pressed
together. Set aside when finished.
¾ While the students are applying the layers of plaster to the cheesecloth, the demonstrator
should prepare the urethane Scotchcast plus® strips for the modern casts. Wearing polyethylene
“rubber” gloves, cut the Scotchcast material into 7 inch strips using the paper guide as a
template. Lay the strips on the empty zipper-bag work surface so they can be easily transported
to the student tables. When you are done cutting six strips, wipe off the shears with a dry paper
towel to remove most of the urethane. Leave the scissors open on the demonstrators table (to
prevent the scissors from sticking shut as any residual urethane cures). Note: Any residual
urethane that has fully-cured on the scissor blades can be removed later with a sharp blade (like a
razor blade) or scraper.
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Experiment 5
Demonstrator’s Guide
¾ When all the tables are done making their plaster cast material…continue with the modern
materials cast.
¾ Have one student at each table wrap his finger with a strip of paper towel and cover a with
glove finger.
¾ The demonstrator should carry the Scotchcast strips and water container to each table and…
¾ Wearing the polyethylene “rubber” gloves, dip the Scotchcast into the water container and
GENTLY (not tightly) wrap it around the student’s finger – have them hold their finger straight!
We want their finger to heal properly! (NOTES: The urethane Scotchcast material has a strong
attachment to skin. Wrap the tip of the finger that is completely covered with the paper towel
and glove finger. Also: The material hardens rather quickly. Do not allow the student to bend
their finger; this helps ensure that the student can easily remove the cast if it sets up too quickly
– although this is not expected under proper supervision.)
¾ Tell the student to remove/slip off the cast from their finger after about a half a minute or
when the material starts to harden and is still slightly flexible (yes they can touch it safely at this
point). (Demonstrators should make sure that each child removes their cast in a timely manner,
so that the cast does not over-harden on their finger. While the cast is expected to be easily
removed if loosely wrapped on a straight finger, it is better to remove the cast while it is still
slightly flexible. Use good judgment!) Repeat for rest of tables.
¾ Ask the students compare their old casting material to the new one. The new material gets
hard very quickly, and stays only slightly flexible. The old material is probably still ‘wet’ and
very flexible at this time. Tell the students they can check on their cast material later in the
program to determine how long it took to finally become hard.
Conclusions
Tell the students the following:
¾ The high tech casting material is made of a piece of mesh material that has been saturated
with chemicals containing short polymer chains and cross-linking agents. You can picture these
as short pieces of a chain (make two interlocked loops with your fingers to demonstrate this
idea). When the material is exposed to water, even water moisture in the air, a reaction starts
that causes the short polymer chains to link together into longer chains. Also, the cross-linking
agents connect them together all along the length of the chains – forming a web or mesh that is
very strong and hard. This reaction happens very fast and allows the doctor to quickly cast a
broken bone such as Millie’s finger.
¾ The old cast material is messier to use and takes more time to harden, making your doctor
visit longer – Who wants that?!
Additional Information If Needed: Technical Background
• None provided; patented information.
National Chemistry Week 2004 - Cleveland Section
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Experiment 6
Demonstrator’s Guide
Experiment 6: Finding the Iron in Cereal
Experiment Purpose & General Methodology
• The students will use a magnet to pull the iron out of fortified cereal.
• This experiment will be done by each table and should take 5 minutes to complete.
Introduce the Experiment
Tell the students the following:
¾ While Millie and Amadeus are at the doctor’s office, the doctor reminds them that they can
do a lot to stay healthy. What do you think he told them to do? Keeping clean – such as
washing cuts and using band-aids, getting enough sleep, getting enough exercise, and eating
right.
¾ Good nutrition is very important. Different foods contain different nutrients and other
healthful substances. No single food can supply all the nutrients in the amounts you need.
¾ The following ‘Eating for Wellness” experiments focus on detecting some of the things in
food that a body needs to keep healthy.
¾ Ask the students if they ever eat cereal for breakfast. Do they look at the nutritional
information on the package?
¾ The nutritional information usually lists some metals that our bodies need to stay healthy.
Ask the students if they can name any of those metals (iron, calcium, sodium, potassium,…).
¾ One of the metallic minerals that are often added to cereal is iron. Iron is one of the elements
in the periodic table. Our bodies need iron to carry oxygen in our blood to other parts of our
bodies. The iron that our bodies need is the same iron that is used to make steel (an alloy of iron
and carbon that forms a strong material).
¾ Ask the students if they know of anything that is made of iron or steel (a hammer, nails, other
tools, cars, skyscrapers, etc.). Ask the students if they can name any of the physical properties of
iron (malleable, ductile, MAGNETIC, etc.).
¾ Tell the students that we will be using the magnetic property of iron to remove it from cereal!
Perform Experiment Simultaneously with the Students
Do the following, leading the students:
¾ Remind the students that we are doing scientific experiments and that they are not to eat or
drink anything that we are using!
¾ Crush the cereal flakes in the zipper-top bag into very small pieces.
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Experiment 6
Demonstrator’s Guide
¾ Open the bag and pour crushed flakes into the clear plastic cocktail-style cup containing
approximately ¼ cup water.
¾ Using the plastic spoon, stir and mash the crushed cereal flakes in the water until they are
thoroughly wet and soggy.
¾ Take the magnet and place it into a bottom corner of empty sandwich bag. Twist the bag
around the magnet and hold it closed with your fingers.
¾ Place the bagged magnet into the cup of soggy cereal and gently move it around for about 30
seconds to one minute. Make sure the magnet reaches down to the bottom of the cup. (This may
require getting the tips of your fingers wet.)
¾ Remove the bagged magnet from the cereal and dip it in the small cup half-filled with water
to rinse off any cereal on the outside of the bag. Don’t brush the magnet too hard on the bottom
or sides of the cup.
¾ Have the students examine the bagged magnet for black specks (the iron) stuck to the bag. It
is likely that the students will not see the black flecks if the magnet is a dark color, so have them
smear the bagged magnet on the piece of white paper (the specks should transfer to the paper)
and/or carefully remove the magnet from the bag, stick your finger into the bag where the
magnet had been, and rub the outside of the bag onto the paper (this should remove any
remaining iron flecks).
¾ The black flecks are the iron that was in the cereal!
Conclusions
Tell the students the following:
¾ Our bodies don’t have specks of metallic iron floating around in our blood. When we eat the
cereal, the acid in our stomachs (approximately equivalent to 0.1M hydrochloric acid) changes
the iron into a different form that can enter our bloodstream. (The metallic iron is oxidized to
Fe2+.)
¾ Cereal makers use the metallic form of the iron because it is stable in storage and it doesn’t
affect the flavor of the cereal. (It is a method approved by the FDA, Food and Drug
Administration.) However, only a small amount of the elemental iron dissolves in stomach acid
due to the limited time the cereal remains in your stomach. (So even if the label says 100% RDA
of iron, it is possible that the body does not get the full percentage.) It is better to eat a complete
breakfast to give your stomach more time to absorb all of the minerals in fortified cereals.
Additional Information If Needed: Technical Background
• Cereals that contain “reduced iron” or “100% iron” are most likely to contain metallic iron.
Total® cereal was selected for this activity because it works very well for this experiment.
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Experiment 6
Demonstrator’s Guide
• Did you know… Spinach has more iron per calorie than meat, but unfortunately, most of the
iron in spinach is not usable because it is bound up by the oxalic acid also found in spinach. In
addition, spinach also contains phytate, a compound that prevents iron from entering the
bloodstream. But you can increase your iron intake by eating spinach with citrus fruits because
foods high in vitamin C enhance iron absorption. (chemistry.org, Veggie Tales, article first
appeared on 2/16/04)
• Calcium and tannins (such as in tea and wine) interfere with iron absorption by the body.
• Iron in our blood is needed to carry oxygen. Some spiders have copper instead of iron in their
blood which makes their blood blue.
• Can a person get too much iron? Yes. Excess iron in the body can lead to a gradual
deterioration of organs, such as the liver, pancreas, and heart. Fortunately, for most people, the
body can regulate iron by controlling the amount that is absorbed from the diet. (ChemMatters,
October 1994, page 14)
• Just for fun… Cereal isn’t the only thing that has metallic iron in it that we don’t usually see.
Dollar bills are printed using an ink that contains iron. If you hold a dollar bill loosely by one
end and hold a strong magnet near the other end, the bill will swing slightly towards the magnet.
(Note – The magnetism is subtle. Don’t expect the dollar bill to fly out of your hand and attach
itself to the magnet!)
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Experiment 7
Demonstrator’s Guide
Experiment 7: Detection of Calcium in Milk
Experiment Purpose & General Methodology
• The students will observe the release of calcium ion into solution by the action of vinegar on
the calcium carbonate contained in Tums®.
• The students will examine the alginate gel that forms, proving the presence of calcium.
• This experiment should take about 5 minutes to complete.
Introduce the Experiment
Tell the students the following:
¾ Ask the students: What is another element that is important for the body to build healthy
bones and teeth? (calcium) Everyone knows that! But what else is calcium used for in the body?
(helps muscles to contract; helps nerves to send messages, and helps to stop bleeding)
¾ Ask the students what foods contain calcium? (dairy products, dark green vegetables, dry
beans, grapefruits, lemons, limes, oranges, peas, salmon, sardines, shellfish, and tofu)
¾ Tell the students that some people take calcium tablets to prevent bone loss and some chew
Tums® (hold up the tablets) to help an upset stomach and get their calcium at the same time.
Students ages 8 need about 800 mg a day but this goes to 1300 mg as you become ten years and
older. It is very important to have enough calcium now to prevent bone loss later. In one study
girls were three times more likely to get broken bones if they drank carbonated beverages instead
of milk.
¾ We will use an interesting method to detect calcium in Tums®.
Perform Experiment Simultaneously with the Students
Part 1 - Preparing the calcium solution
Do the following:
¾ Show the students the bag with the six Tums® tablets.
¾ Ask for a volunteer to crush the Tums®. Hand him or her the metal spoon you brought from
home (the plastic spoon is not as durable as needed). If the tablets are too hard for the students to
crush, crush them partially yourself and then let the student finish. Be sure they crush the tablets
while still sealed in the baggie to prevent making a mess, and crush them into a fine powder.
¾ While the student crushes the tablets, the demonstrator is to pour the vinegar from the bottle
into the large plastic cup.
¾ Tell the students that the Tums® contain a base which reacts with acid, typically in
someone’s stomach, to make a neutral solution - that’s why Tums® helps to soothe an acidic
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Experiment 7
Demonstrator’s Guide
stomach. Show the students the vinegar in the cup and tell them that this is the acid that the basic
Tums® will neutralize.
¾ Add all the Tums® powder slowly and carefully to prevent the solution from overflowing the
container. Swirl the solution until the bubbling stops. Ask the students: What gas was produced?
(carbon dioxide). That’s why many anti-acids also contain anti-gas medicines.
¾ While you swirl the solution, tell the students that each Tums® tablet contains calcium in the
form of calcium carbonate. You have just performed a neutralization reaction between the acidic
vinegar and basic carbonate-portion of the calcium carbonate. By reacting carbonate in the
calcium carbonate with the acidic vinegar, the calcium is released into solution.
¾ Tell the students that now that we’ve released the calcium into the solution, we can detect it.
¾ The demonstrator should now pour nearly equal amounts of this new calcium solution into
each of the plastic cups. Distribute one cup to each table including your demo table.
Part 2 - Detecting calcium by preparing an alginate gel using sodium alginate
¾ Fill the beral pipet with the alginate solution and add it to your demonstration cup by allowing
a continuous stream to flow into the solution in a lazy “S” pattern. The demonstrator should then
go to each table and give them one beral pipet full of the alginate solution into their calcium
solution cups.
¾ Tell the students that we all must not disturb the material until all the cups have been filled.
Optional: Pour some calcium fortified orange juice into the clear cup you brought from home,
and add the alginate to this as well.
¾ While moving around the room let the students know that you are giving them sodium
alginate a polysaccharide, just like the starch in potatoes is a polysaccharide made of long chains
of individual sugar molecules. But this material is derived from brown seaweed, Giant kelp, and
is often used as a thickening agent in food products. One of the most interesting properties of
alginates is the ability to form gels by reaction with calcium ions. It produces a cross linked
alginate polymer; in other words, it takes the chains of the polysaccharide and hooks them
together along the chain. Tell the students that if they have made and/or played with Slime and
GAK (at home or at our programs in the past), those materials are also cross-linked polymers.
¾ Tell the students that they can get their recommended daily allowance of calcium if they drink
about three glasses of milk, or eat 2 cups of yogurt, 4 cups of spinach, or 15 oranges.
¾ When all the tables have received their alginate, return to your sample and remove the gel
onto a paper towel using the plastic spoon. You need to wait until at least one minute has passed
from the last table dispensed to form a good gel.
¾ If it’s been a minute since they received their alginate, have each table remove their material
with the plastic spoon onto the paper towel or onto the newspaper covering the table. Ooey,
gooey fun! Examine the gel formed. Ask the students for their reaction to the gel—texture,
color.
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Experiment 7
Demonstrator’s Guide
Conclusions
Tell the students the following:
¾ Diffusion of the calcium ion over time will change the character of the polymer. When the
alginate solution is poured into the calcium ion solution, the calcium alginate will form on the
surface of the sodium alginate stream almost instantly. The shape will be maintained if
undisturbed. Initially, the center will be unreacted sodium alginate, but over a short period of
time the soluble calcium will diffuse into the center and form a complete calcium alginate
structure. The rigidity of the polymer will increase as this diffusion occurs.
¾ Explain that while calcium forms this gel, magnesium and iron (which are other common food
additives) do not do this. Thus, this is a good test for the presence of added calcium in our
TUMS® tablets, orange juice, and other items.
¾ Students may let the sample sit in their solution and examine it at the end of the program.
This will add another minute or two to your program however.
Additional Information If Needed: Technical Background
CaCO3 (s) + CH3COOH (l) ---> CO2 (g) + H2O (l) + Ca+2 (aq) + CH3COO-1 (aq)
• Sodium alginate is commercially produced by food manufacturers from brown seaweed
known as Giant kelp, Macrocystis pyrifera. Only mature beds of this abundant perennial are
harvested. Sodium alginate as well as calcium alginate are used in the food and drug industry as
stabilizers, emulsifiers and thickening agents in products such as puddings, ice creams, fruit
fillings and toppings, pharmaceutical tablets, ointments, lotions and shampoos.
• Under the proper conditions, sodium alginate will react with calcium ions to form an instant
gel which will become firmer over time, retaining their shape and resisting stress. Slowly pouring
a sodium alginate solution into a calcium ion solution, results in the cross-linking reaction to form
a worm-like gel.
• Careers in Food Science are often overlooked, but this is a great opportunity to explore some
of the properties of food additives.
• Alginate is a polysaccharide composed of three kinds of polymer segments. One segment is
mainly D-mannuronic acid units, the second is mainly L-guluronic acid units, and the third
segment consists of alternating D-mannuronic acid and L-guluronic acid units. Actual
composition depends upon the source.
• The Tums® tablet contains calcium ion in the form of the insoluble calcium carbonate which
is released into solution by the action of the acetic acid in vinegar, producing carbon dioxide and
water as a byproducts. The color of the TumsTM does not interfere with the experiment. The pH
needs to be slightly acidic to form the “worms”; this is accomplished with the addition of excess
acetic acid or vinegar.
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Experiment 8
Demonstrator’s Guide
Experiment 8: Testing for Carbohydrates - Starch
Experiment Purpose & General Methodology
• The students will use an iodine solution to detect the starch in potato flakes.
• This experiment will be done by each table and should take less than 5 minutes to complete.
Introduce the Experiment
Tell the students the following:
¾ More on nutrition! Minerals, such as iron and calcium, are generally called micronutrients
because our bodies need them in fairly small quantities. But our bodies also need various
macronutrients, nutrients in larger quantities, such as water, carbohydrates, fats and proteins.
¾ Carbohydrates and fats are made up of chemicals that provide energy for your body to
perform its daily activities. Proteins are needed for growth and repair.
¾ There are two groups of carbohydrates, simple and complex. Simple carbohydrates are
mono- or disaccharide sugars, which tend to taste sweet, form crystals, and dissolve in water.
Complex carbohydrates, or polysaccharides, are made of many connected saccharide (sugar)
molecules.
¾ The two main complex carbohydrates in your diet are starch and dietary fiber. Although
starches are made from chains of sugars, they do not taste sweet. (Food and Nutrition for Every
Kid, Janice VanCleave)
¾ Our bodies need the starch and dietary fiber of complex carbohydrates for good health. Foods
that contain complex carbohydrates often contain other nutrients that our bodies need. Simple
carbohydrates, like refined sugar, often provide calories, but few other benefits.
¾ Although starches and sugars have many similarities, they do not behave the same
chemically. Elemental iodine reacts with complex carbohydrates, like starches, to turn a blueblack color, but it does not react with simple carbohydrates, like sugars. We will investigate the
reaction of iodine with various carbohydrates.
Perform Experiment Simultaneously with the Students
Do the following, leading the students:
¾ Again, remind the students that we are doing scientific experiments and that they are not to
eat or drink anything that we are using!
¾ Locate the two plastic cocktail-style cups each containing ¼ cup of water. Add the potato
flakes to the cup marked “pot”; add the sugar to the other marked “sug”.
¾ Stir the contents of each cup with its own stirring stick. Stir until the sugar dissolves. (The
potato flakes will not completely dissolve.)
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Experiment 8
Demonstrator’s Guide
¾ Demonstrator - Cut open the sealed pipette containing the iodine with scissors. Go around to
each table and add iodine to the potato flake “solution” until it turns a blue-black color that
persists (about 5 – 10 drops).
¾ Add the same number of drops to the sugar solution. Caution: Iodine is poisonous if
ingested. Do not allow children to handle iodine solution.
¾ The iodine turns the potato flake “solution” a blue-black color, the iodine remains brown in
the sugar solution!
¾ NOTE: If the color of the potato flake solution fades before moving on to the next
experiment, go back and add a couple of drops of the iodine to the cups.
Conclusions
Tell the students the following:
¾ Starch is a polymer (long chain) consisting of glucose (a sugar) monomers (units). It is found
in rice, wheat, potatoes, grains, and cereals.
¾ The iodine test causes starch to react strongly with iodine to form the characteristic deep
black-blue color. Other polysaccharides like cellulose also react with iodine to form color.
Polysaccharides react with iodine because the long chains loop and tangle, and the iodine is
trapped in the middle, forming an iodine-starch complex. Mono- and disaccharides (like the
simple sugars) do not react with iodine.
Additional Information If Needed: Technical Background
• The four major groups of biological molecules are: carbohydrates (sugars), lipids, proteins,
and nucleic acids. Monosaccharides (e.g. glucose) link together to form polysaccharides (e.g.
starch, glycogen, cellulose). (http://www.usd.edu/biol/labs/151/chem51.htm)
• Carbohydrates are chemicals in food that are made of carbon, hydrogen, and oxygen, and
come mainly from plants.
• Sugar is a simple carbohydrate. There are "single" (mono), "double" (di-) and "triple" (tri-)
sugars (saccharides) Sugars are a source of food for plants and animals. Many different kinds
of sugar exist in nature but only three are found in any quantity in the kitchen: glucose, fructose,
sucrose. Glucose and fructose have the same chemical formula -- C6H12O6 -- but slightly
different molecular structures. They are the major components of honey. Sucrose, table sugar, is
one glucose molecule and one fructose molecule joined together.
• Starch is a complex carbohydrate. It is a polymer consisting of thousands of glucose
molecules linked together. Picture a train made up of thousands of identical cars. Seventy-five
percent of starch is amylopectin (branched glucose polymer). Twenty-five percent of starch is
amylose (linear glucose polymer).
• Starch is produced by plants from sugar photosynthesized in leaves. While sugar is soluble
in water, starch is not. Plants deposit starch in tiny granules (2-50 micron) whose size, shape and
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Experiment 8
Demonstrator’s Guide
composition vary depending on the plant (wheat, barley, rice, maize, oats, rye). Grains have to
be milled and refined to remove their tough, protective layers and make them easier to cook and
to chew.
• Instant Potato Flakes are dehydrated potato with emulsifier (mono and diglycerides) and
preservative (sodium acid pyrophosphate, sodium bisulfite, citric acid). Potato plants are
relatives of tobacco and tomato. Potato was originally cultivated in the mountains where corn
could not grow. There are two types of potatoes. Mealy are used for baking and mashing. They
will sink in salt water. Waxy are used for potato salad and will float in salt water.
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Experiment 9
Demonstrator’s Guide
Experiment 9: Vitamins! Vitamins!
Experiment Purpose & General Methodology
• The students will use the iodine-containing potato flake solution from experiment #8 to see
the effect of vitamin C on the iodine-starch complex. The students will also observe the
fluorescence of some of the components of a multivitamin.
• The first part of this experiment will be done by each table. The second part will be done as a
demonstration. The entire activity should take less than 5 minutes to complete.
Introduce the Experiment
Tell the students the following:
¾ More nutrition! Vitamins are organic substances (substances that contain carbon) that your
body needs for normal growth and metabolism. There are many different vitamins and they are
named with letters from the alphabet: A, C, D, E, K, and eight different B’s (B1, B12, etc.). Only
vitamins D and K can be made in your body. You must eat foods that have the other essential
vitamins you need. (Food and Nutrition for Every Kid, Janice VanCleave)
¾ Vitamins A, D, E, and K are fat-soluble, which means they dissolve in fat and can be stored
in the body. Vitamin C and the B vitamins are water-soluble, meaning they dissolve in water.
Water-soluble vitamins are not stored by the body for any length of time, but are washed out of
the body, mainly in urine.
¾ Vitamin C is an antioxidant, which means it inhibits (decreases or stops) the process of
oxidation. Some oxidation reactions cause our bodies to age over time.
¾ In Experiment #8, when iodine is mixed with starch, a black-blue color is formed. If vitamin
C is added, the vitamin C reacts preferentially with the iodine so the starch does not and the
black-blue color is not formed (or in our case, the blue-black color goes away).
Perform Experiment Simultaneously with the Students
Part I – Vitamin C
Do the following, leading the students:
¾ Show the students the chewable vitamin C tablet (it’s the round, orange tablet). The chemical
name for vitamin C is ascorbic acid.
¾ With the vitamin C tablet inside its bag, carefully crush the tablet with the sturdy metal
spoon (brought from home).
¾ Pour the vitamin C powder into the cocktail cup marked “vit C” containing ½ cup water and
stir with a stirring stick until the powder is mostly dissolved.
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Experiment 9
Demonstrator’s Guide
¾ Quickly distribute the vitamin C solution among the 7 small paper cups and place one cup on
each table.
¾ Have the students locate the blue-black colored potato flake “solution” from the previous
experiment.
¾ Using the pipette, students should carefully add a few drops of the vitamin C solution to the
potato flake “solution” and stir. Continue adding drops of vitamin C and stirring until blue-black
color disappears.
Conclusions for Part I – Vitamin C
Tell the students the following:
¾ Vitamin C (ascorbic acid, C6H8O6) interferes with the iodine test. The vitamin C reacts
preferentially with the iodine so the starch does not react and the blue-black color goes away.
¾ Most animals possess an enzyme needed for making ascorbic acid from glucose, but humans
and a few other species lack that enzyme. Humans must obtain ascorbic acid (vitamin C) from
the food they eat.
¾ To maintain good health, the current recommended daily allowance (RDA) of vitamin C is
60mg. Foods like fruits and vegetables with high water content often contain large amounts of
vitamin C.
Introduce Part II – Multivitamins
Tell the students the following:
¾ Some vitamins do more than just keep our bodies healthy. Some vitamins are fluorescent
under UV light. This property does not necessarily make the vitamins better, but it is fun!
Part II – Multivitamins
Demonstrate the following for the students:
¾ Remove the multivitamin tablet from its bag and show it to the students (it’s the yellowishbrown oblong tablet). Turn on the UV light and turn down the room lights (if possible) and show
the students that the multivitamin tablet glows slightly yellow.
¾ Break the vitamin in half (using the side of the sturdy spoon brought from home) and place
half of the tablet back in the zipper-top bag.
¾ Carefully crush the half tablet in the bag and pour the powder into the cocktail cup marked
“MV” containing 2 tablespoons water. Stir with a stirring stick until the powder is well dispersed
(it won’t fully dissolve).
¾ Again, turn on the UV light and turn down the room lights (if possible). This time, the
vitamin “solution” will glow more brightly yellow and should be easier for all to see.
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Experiment 9
Demonstrator’s Guide
Conclusions for Part II - Multivitamins
Tell the students the following:
¾ Why does the multivitamin glow? Vitamin A, the B vitamins (notably B12), thiamin, niacin,
and riboflavin are all fluorescent. The multivitamin used in this demonstration contained 100%
RDA of all of the vitamins and minerals listed above.
Additional Information If Needed: Technical Background
• Fluorescent substances absorb ultraviolet light and then re-emit it almost instantaneously.
Some energy gets lost in the process, so the emitted light has a longer wavelength than the
absorbed radiation, which makes this light visible and causes the material to appear to “glow”.
(from About.com, Chemistry)
• Vitamin A – Keeps eyes, skin, and hair healthy. Helps form teeth and bones. Helps keep
body’s defenses strong. Found in broccoli, carrot, cantaloupe, dairy products, eggs, spinach, and
sweet potatoes.
B vitamins (B1, B2, B3, B6, B12) – Helps the body use nutrients. Help keep brain and nerves
healthy. Help to heal injuries and fight disease. Help keep skin and eyes healthy. Found in whole
grain breads, cereals, beans, peas, brown rice, and nuts.
Vitamin C – Helps to hold body cells together, heal cuts, and fight disease. Helps keep gums
healthy. Helps in forming teeth and bones. Found in broccoli, cantaloupe, cauliflower, lemons,
oranges, limes, grapefruits, kiwis, tomatoes, and potatoes.
Vitamin D – Helps to build strong bones and teeth. Helps to keep the right amounts of
calcium and phosphorus in the blood. Found in butter, eggs, margarine, and milk.
Vitamin E – Helps to make muscles and red blood cells. Helps to protect body tissues from
damage. Found in eggs, fish, leafy vegetables, dry beans, nuts, peanuts, peas, whole-grain breads
and cereals.
Vitamin K – Helps to stop bleeding. Helps to keep bones strong and healthy. Found in
cabbage, cauliflower, cereals, dairy products, eggs, green leafy vegetables, meats, peas, and tea.
(from “Eat your Vegetables! Drink Your Milk!”, by Dr. Alvin Silverstein, Virginia
Silverstein, and Laura Silverstein Nunn)
• Vitamins – What happened to vitamins F, G, H, and I? And why are there so many extra Bs?
None of the vitamins are really missing. The first ones that were discovered were named in
alphabetical order. (The chemical names came later when scientists found out more about them.)
The Danish researcher who discovered vitamin K named it after the Danish word for clotting,
Koagulation, because vitamin K helps the blood to clot. Meanwhile, scientists had found that
what they thought was a single B vitamin was really a group of vitamins that are usually found
together in the same foods. So numbers were attached to the B. By the time the last of the B
vitamins were discovered, the system of letter naming was out of style; thus some of the B
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Experiment 9
Demonstrator’s Guide
vitamins are called only by their chemical names. (from “Vitamins and Minerals”, by Dr. Alvin
Silverstein, Virginia Silverstein, & Robert Silverstein)
• Did you know… Some foods contain antivitamins, chemicals that prevent vitamins from
working in the body. Some kinds of fish, for example, contain the enzyme thiaminase, which
breaks down thiamine into forms the body can’t use. Heat destroys the enzyme, so when fish is
cooked, its thiamine can be used by the body. (from “Vitamins and Minerals”, by Dr. Alvin
Silverstein, Virginia Silverstein, & Robert Silverstein)
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Closing Session
Demonstrator’s Guide
Closing Session
Close Demonstration
¾ Thank the students and parents for coming to this year’s demonstration and learning about
the chemistry of health and wellness. Tell the students that you will now collect the goggles and
give them some items to take home to continue having fun with chemistry at home.
¾ Collect the goggles and hand out the literature for all the students: Celebrating Chemistry
newspapers, Booklists, Activity Sheets, etc.
¾ Tell the students that you have only 10 copies of ChemMatters magazine, which is written for
older children, and that if they have an older brother or sister or good friend that they may want
to take one home for them.
Clean up
After the students leave, clean up the room
¾ Return items borrowed from the library to a librarian. Give any leftover literature to the
librarian.
¾ Rinse the vial with water and dry with a paper towel. Place it along with the Gore-tex
glove(s), UV-beads, and magnets into the large mailing envelope to be returned to the Solon,
CCPL library.
¾ In the liquid-waste gallon jug, combine all water first. This liquid waste can be put down the
sink safely with running water.
¾ All solid waste can be collected in the large garbage bag and thrown into the regular trash.
¾ If you are performing another demonstration for this year’s National Chemistry Week,
sanitize the goggles between demonstrations with a dilute bleach solution as instructed in the
written directions found on the inside cover of the goggle container. Be sure to dry them with
soft cloth to prevent scratching.
¾ If you are finished performing your demonstration(s) for this year, place the used goggles
into their box. (There is no need to clean them when you are through. Our committee will clean
them for the next year and/or for other programs.)
¾ Give the envelope, the UV light (in its shipping container), as well as the box of goggles to
the children’s librarian with instructions to put it them in the interlibrary mail to Solon.
At home:
¾ Cured urethane reside on your scissors/shears can be removed using a razor blade at home.
¾ E-mail Kat at [email protected] with the number of students and adults at your program
and any comments you have to improve our programs in the future.
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Appendix
Demonstrator’s Guide
Appendix
A. Material Safety Data Sheets
None necessary. All materials can be purchased at local stores.
B. Kit Contents – Supplemental List of Solutions and Special Supplies
The following is detailed information that can be used to recreate this demo kit in the future:
Experiment 1 - The Gore-Tex® gloves were donated from W.L. Gore and Associates, Inc. but
similar materials are available in local outdoor clothing suppliers.
Experiment 2 - The UV color-change beads are available from Educational Innovations
(www.teachersource.com) or at some craft stores.
Experiment 3 - Calcium carbonate can be found as the product Damp Rid® (moisture-absorbing
product for closets, basements, etc.) available at grocery and general merchandise stores. Citric
acid can be purchased as Sour Salt, available with other spices, at grocery stores.
Experiment 4 – Glo-Germ lotion is available from Educational Innovations
(www.teachersource.com). A similar product is available from Brevis Corporation
(www.brevis.com) as Glitter Bug® potion.
Experiment 5 - The modern casting material (3M Scotchcast plus®) was donated from 3M but is
available in local pharmacies.
Experiment 6 - Total® cereal seems to work best for this experiment. Other cereals may also
work, but should be tested first.
Experiment 7 - Sodium alginate is available through Kelco. In 2004, you can contact Lois
Kuhns at [email protected] to request enough to make 250 ml of solution. She has a
limited supply; first come, first served. Otherwise, most is from China and can be obtained
through the internet.
Experiment 8 - Standard tincture of iodine, available in pharmacies, can be used.
Experiment 9 - The multivitamin should be high in vitamins A and B, thiamin, niacin, and
riboflavin. Not all multivitamins will exhibit strong fluorescence – check to make sure the one
you are using is sufficient.
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