You Be The Chemist

Introduction
Your LabZone Connection

Teacher's Notes
The Great Ketchup Caper
Goofy Putty
Great Salt Golf Ball
Original Bubble Chamber
Puffed Rice Fleas
Iron in Cereal
Diaper Polymers
Sewer Leeches
Ghosts in the Bathroom
Rusting Wool
Rubber Bones
Water Optic Cable

Introduction

The "You Be The Chemist" (YBTC) program and kit were developed by the Chemical Educational Foundation (www.chemed.org). The Chemical Educational Foundation (CEF) is a national non-profit organization that works through the chemical industry to promote the importance of chemistry, chemicals, and chemical safety awareness education.

The YBTC kit offers new and different techniques to:

• serve as a teacher's aid to engage students in science.
• make chemistry concepts fun and easy for students and teachers.
• provide an outreach tool for the chemical industry.
• emphasize the role of chemicals in our everyday lives.

The YBTC kit contains 30 hands-on, student-centered lesson plans that cover topics such as scientific inquiry, the structure of matter, and safety and recycling (see www.chemed.org/Lesson_Plans.htm). In order to make real-world connections to chemistry and create a more teacher-friendly curriculum, experiment materials consist of small amounts of common, nontoxic household items. In addition to inquiry-based activities, the YBTC kit contains homework, assessments, vocabulary, puzzles, historical connections, and writing assignments See www.chemed.org/Kit.html.

The purpose of this program is to provide both teachers and students a set of activities based on science process skills. The selected activities complement emerging national and state learning standards and assessment efforts. Not only are these activities fairly inexpensive to perform, they are captivating for students. Each activity is based on both content and skill activities found in any basic chemistry curriculum.

A chemist never forgets that the human body is a mobile and vulnerable chemical factory and should be protected at all times, especially from dangerous chemicals or lab situations. Be safe. Follow the safety protocol mentioned in these activities.

You can be the chemist. Chemistry is not only for special people in special laboratories. It is everywhere, involved with everything and everyone. Take the first step toward becoming a chemist by delighting in the skills you'll build performing the activities within the program.

The SNK LabZone features a selection of activities from the "You Be The Chemist" program and kit. The following notes provide teachers with hints on how to use this material in the classroom.

Teacher's Notes: The Great Ketchup Caper

Description: A series of acids and bases are used to attempt to clean ketchup stain.

Science Process Skills: observing, measuring, recording, analyzing.

Content Topics: molecules, acids, bases, solutions, chemical reactions.

Instructions: During this activity, you will try different cleaning methods using mild acids and bases, predicting, testing. and measuring results.

Presentation:

1. Tell students that when you attempted to eat lunch the ketchup squirted on your T-shirt instead of your food. Since you do not have laundry detergent at school, you want them to test various "home remedy" stain removers. The three chemicals you have chosen are lemon juice, club soda, and baking soda. Explain that club soda is similar to soft drinks (something the kids are familiar with) except it has no sugar. You may need to explain, or ask the students if they know of, different uses for baking soda.

2. Ask students to inspect the three substances by describing their physical characteristics.

3. Have the students predict which substance will be the best cleaner. In addition, have them predict the amount of time that it will take to remove the stain.

4. Ask students whether or not the stirring has anything to do with cleanliness. Remind them of the purpose of an agitator in a washer.

5. Have students put together a list of variables that might affect stain removal. Examples: time in cleanser, amount of agitation, cloth used (Does polyester clean as well as cotton?).

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Teacher's Notes: Goofy Putty

Description: A borax and water solution are mixed with a glue and water solution to create a polymer.

Science Process Skills: observing, measuring, recording, analyzing.

Content Topics: molecules, polymers, solutions, chemical reactions.

Instructions: During this activity, you will be measuring and mixing solutions. If the measurements are not exact, the experiment will not work correctly.

Presentation:

Ask students where metal comes from. [mined ore, rocks] Paper? [trees] T-shirt? [cotton plants] Glass? [sand] Ask them where plastic comes from. Many will not know that most plastics are petroleum products. Explain to students that scientists called chemists know how to design and make molecules with special properties. Chemists learned how to hook atoms into long chains called polymers. Plastics are made of polymers. Some polymer molecules contain thousands or millions of atoms in long chains.

1. Allow students to inspect the borax, making notes in their journals describing the physical characteristics of borax. [White, grainy, powder.

2. Direct students to make notes as they observe the steps of the process. What physical characteristics change?

3. Ask students to observe and note physical characteristics of the rubber-like polymer. [Slightly elastic, becoming brittle in a few hours.]

4. Ask students to suggest reasons for the change in physical characteristics. [Changes in molecular structure.]

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Teacher's Notes: Great Salt Golf Ball

Description: A density gradient is created and demonstrated with salt water and a golf ball.

Science Process Skills: observing, measuring, comparing, analyzing.

Content Topics: solubility, density, buoyancy.

Instructions: This activity can require several days to several weeks to complete and makes an excellent semester project. Establish a site for the cylinder to remain on display and undisturbed for that length of time.

Presentation:

1. After you have prepared the cylinder, ask students to describe the contents of the cylinder. [The cylinder contains salt in the bottom, a golf ball resting on the salt, and is filled with water.]

2. Ask students to predict what might happen as the very soluble salt is allowed to remain under water for an extended period of time.

3. Ask students to occasionally measure and record the height of the golf ball in the cylinder without disturbing the contents.

4. After the ball appears to have stabilized at a given height, ask students to explain the phenomena.

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Teacher's Notes: Original Bubble Chamber

Description: A carbonated beverage and salt crystals demonstrate how invisible particles can be detected.

Science Process Skills: observing, analyzing.

Content Topics: solubility, ionization, subatomic particles

Instructions: Make certain the tall glass vessel is immaculately clean. A 500 ml graduated cylinder works well for this activity. A funnel-shaped glass works even better.

Presentation:

1. Remind students that scientists must often work with objects too small to be seen with the human eye.

2. Ask students to share any experience they have had detecting something that is too small to be seen.

3. Ask students to imagine how scientists detect particles the size of atoms or molecules.

4. As you drop the single grain of salt in the carbonated beverage, ask students to describe what they observe. [Rising trail of bubbles.]

5. Allow students to repeat the activity several times. Instruct them to use smaller and smaller grains with each trial. Ask them to create the smallest detectable grain of salt possible with the tools they have at hand.

6. Ask students to try this activity with a material other than salt. Suggest common sand. [Clean sand should not create a bubble trail.]

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Teacher's Notes: Puffed Rice Fleas

Description: Kernels of puffed rice cereal behave like fleas when charged with static electricity.

Science Process Skills: observing, analyzing, manipulating materials.

Content Topics: chemistry of electron interaction: a demonstration static electricity and like/unlike charges

Instructions: This activity works best in low-humidity conditions.

Presentation:

1. Ask students to observe the invisible legs on the fleas placed on the plate, noticing how large the legs are and how they are used for jumping.

2. Charge the balloon or comb out of view of the students. If that is impractical, suggest you are merely using a rag to clean the balloon before bringing it near the fleas.

3. Ask students to observe the jumping action of the fleas as the balloon is brought near to the kernels of rice.

4. Ask students to explain the jumping action of the fleas.

5. Allow students to manipulate the cereal and charging items, determining the best method for flea jumping.

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Teacher's Notes: Iron in Cereal

Description: A small magnet is used to remove particles of iron from common breakfast cereal.

Science Process Skills: observing, analyzing, measuring.

Content Topics: hemoglobin, food digestion, human physiology, diet

Instructions: Place the entire contents of a box of flakes into a large bowl. Use your hands to crush the flakes to pin-head size pieces. Add water and stir. Use additional water to keep the mixture thin and soupy. Tape a small magnet on the end of the glass rod. Stir the cereal soup with the magnet for several minutes. Small bits of pure iron will collect on the magnet!

Presentation:

1. The demonstration requires 15 to 20 minutes of stirring or mixing. The particles of iron are very tiny. The mixing process dislodges them from the flakes. Following the description on the side of the cereal box, direct students to collect the amount of iron included in the "recommended daily allowance." You may not have a milligram balance, but students can make a rough determination. Allow them to develop their own plan for how they might determine this number.

2. They should remove as much iron from the "soup" as possible. The iron should be washed with a few drops of water and dried on absorbent paper. Students can use the cereal box to determine the number of servings included in the box. They can divide the iron into that many equal piles.

3. At the beginning of the activity, you may want to present a large iron nail or spike and ask students if they would like to eat some of it. You can also use a metal file to scrape off small pieces to make the iron more palatable for the students!

4. In activities related to technology and earth science (mining), you may want to allow students to develop their own methods for "iron extraction."

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Teacher's Notes: Diaper Polymers

Description: Super-absorbent polymer crystals are removed from diaper fibers.

Science Process Skills: observing, analyzing, application.

Content Topics: chemistry, polymers, molecular bonding

Instructions: Remove the fiber filling from a disposable diaper. Looking at it through a magnifying lens, you will notice tiny flakes or crystals attached to the filaments. In some brands, these filaments are obvious without a microscope.

Presentation:

1. Remind students that chemists design and manufacture molecules to perform everyday tasks. The molecule in the diaper crystals is designed to attract and hold liquid.

2. Before class begins, place a spoonful of crystals into a paper or Styrofoam cup. Demonstrate to students that you are pouring water into an "empty" cup. Stir the water for a few seconds. Invert the cup. Nothing falls out. Ask students to describe what mechanism was responsible for retaining the water in the cup.

3. Direct students to develop a list of other possible uses for a water-attracting molecules.

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Teacher's Notes: Sewer Leeches

Description: Students create imaginary creatures with soda and raisins.

Science Process Skills: observing, analytical thinking, inferring.

Content Topics: density, life cycles, solubility of gases

Instructions: Fill the tall cylinder with 7-Up®, club soda, Mt. Dew®, or some other clear, carbonated soft drink. Drop a small handful of raisins into the cylinder.

Presentation:

1. Prepare the soda-raisin mixture before class begins. Cover the cylinder with a towel. Inform students that you have collected some sewer leeches. You have them covered because they normally live in dark surroundings and do not favor bright lights. From a distance, students cannot identify the moving creatures as raisins. A little food coloring or dye will tint the water to make the effect more believable.

2. Inform the students that the creatures in the cylinder have the characteristic shape of the larval stage of development and will soon hatch. Use some forceps or a net to catch one of the leeches. You might even want to bite one, for effect!

3. The students soon surmise that you are fooling them. Allow them to make close observations of the creatures in the cylinder.

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Teacher's Notes: Ghosts in the Bathroom

Description: A steamy bathrrom reveals the handwriting of ghosts on the bathroom mirror.

Science Process Skills: measuring, observing, analyzing.

Content Topics: surface tension, soaps and detergents, humidity

Instructions: This is a great activity for students to perform at home. You may have to practice a few times to develop a successful soap writing technique.

Presentation:

Tell the students that a friendly ghost haunts your bathroom. He leaves you little messages in the morning on your bathroom mirror. Don't the students have a similar ghost? Well, then it is not a ghost, what could it be? Tell them the messages only appear when the bathroom is all steamy and the door is locked, so you are certain that no one has entered while the shower curtain is closed. This can lead to discussions on condensation, writing on cold windows, etc. Let students develop several hypotheses and test them. After this discussion, let them know that you are the ghost and fill them in on your soap writing technique and the content behind the writing. Then, they go home and surprise their families.

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Teacher's Notes: Rusting Wool

Description: Steel wool combines with oxygen in controlled conditions.

Science Process Skills: observing, analyzing.

Content Topics: chemical reactions, oxygen and oxidation, composition of atmosphere

Instructions: Do not use steel wool pads that contain soap or cleaners. Use 0000 steel wool. It is sold in hardware and paint stores.

Presentation:

1. Ask the students to describe the composition of common air.

2. Ask students to explain the importance of oxygen to living creatures.

3. Ask students how the atmosphere's supply of oxygen is renewed.

4. Ask students to describe oxygen's role in common combustion.

5. Ask students to monitor the water level in the jar. Make a mark to indicate the interior water level. Why is the water rising in the jar? Is there less gas than initially placed in the jar?

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Teacher's Notes: Rubber Bones

Description: Bones and raw eggs are soaked in vinegar.

Science Process Skills: observing, analytical thinking, measuring, recording.

Content Topics: chemical reactions, skeletal system, diet

Instructions: The materials used in this activity are completely safe. However, the process can be messy.

Presentation:

1. Ask students to inspect the bone before it is placed in vinegar. What gives a bone its strength? [Calcium in cell walls.] What would be the effect on a person if there were no calcium in his or her bones? What might happen if there were too much calcium?

2. What purpose does the shell of an egg serve? What would happen if the structural calcium were removed from the eggshell?

3. What are the sources of calcium for people? What is the source of calcium for chickens?

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Teacher's Notes: Water Optic Cable

Description: Internal reflection is created in a small water stream, replicating polymers that function similarly.

Science Process Skills: observing, analyzing, comparing, modeling

Content Topics: reflection, fiber optics, materials chemistry

Instructions: This activity can be a bit messy. Give appropriate forethought to dealing with the water involved.

Presentation:

1. Ask students to share their person experiences with optic cables. [Fiber optic art pieces, cable television access cables, etc.]

2. Ask students to describe how they think fiber optic cables might work. How does light travel through cables without leaking out?

3. Suggest to students that you have a model fiber optic cable.

4. Allow students to operate the water optic cable several times. Ask them to make and share their observations. What evidence do they observe that suggests that light travels within the confines of the water stream? [The brilliant spot of light at the splash point.]

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