What Music Does Bacteria Enjoy the Most?

Grade Level: 9th to 12th; Type: Biology

Objective:

This experiment will explore whether music of different varieties affects the growth of bacteria.

Research Questions:

• Does music alter the growth of bacteria?
• Do different kinds of music make the bacteria grow differently?

Although bacteria lack the ability to hear, they are very perceptive to changes in vibration. Physically speaking, music is essentially various changes in vibration. This experiment might help figure out better ways to process sewage and other essential microbe-assisted duties.

Materials:

• 2 or more prepared Petri dishes with agar (available from biological supply companies)
• Sterilized swabs
• Rubber or plastic gloves
• 2 or more portable CD or MP3 players
• Several pairs of cheap headphones, NOT earbuds (same number as music players) You will want to throw them away after the experiment.
• Several songs or albums of various music, the more diverse the better (such as classical, hard rock, and dance)
• Camera
• Notepad and paper
• Ruler

Experimental Procedure

1. Wearing gloves, prepare the Petri dishes. Following the manufacturer’s instructions, take them out of the refrigerator for about an hour before conducting the experiment.
2. Using the sterilized swabs, collect bacterial samples while wearing gloves. Good places to nab some bacteria include faucets or any other area that is touched by a lot of people. Ensure that you swab from the same area to get roughly the same amount and type of bacteria. Swipe the swab against the agar in the Petri dish and then close and seal the dish. Label each sample.
3. Place the samples in a warm, out of the way place. Leave one sample alone, this is the control.
4. For the other samples, place the headphones snugly around the dish.
5. Connect the headphones to the music players. Play a different song or album on repeat on each player.
6. Let the samples grow for a week. Make sure to keep the music players charged and playing at all times. Take pictures of the developing bacteria everyday.
7. Take off the headphones and compare each sample. Take note of the amount of colonies in each sample and measure the size of each colony.
8. Carefully dispose of the Petri dishes.
9. Analyze this data. Did the music have an affect on the size or amount of bacteria colonies? Did a certain genre of music have a greater affect than others?

Terms/Concepts: microbiology, bacteria, microbes, vibrations, sewage treatment

0

Laser Jet Toner: a Magnetic Fluid

Grade Level: 7th to 9th; Type: Physical Science

Objective:

In this experiment, you will experience a magnetic fluid as it moves, bubbles, and forms unique shapes.

Research Questions:

• Why does the fluid contort into different shapes?
• Are there other fluids that are magnetic?
• What makes them magnetic?

Materials:

• Magnets of varying size and strength
• Laser jet toner (Ferro fluid)
• Beaker
• Pure vegetable oil
• Stirring stick
• Long, clear bottle, jar or flask

Experimental Procedure

1. Pour 50mL of toner into the beaker.
2. Pour in 30mL of pure vegetable oil.
3. Stir it to a nice thin consistency. (If it is too thin, it might not work properly.)
4. Pour the mixture into the long container.
5. Touch a magnet to the container. Observe what happens to the fluid. (It should move with the magnet and contort into intriguing shapes.)
6. Experiment with using other magnets. See what happens when you drop the magnets into the liquid.

Terms/Concepts: magnetism, magnetic fluid

0

When Air Masses Collide

Grade Level: 7th to 10th; Type: Meteorology
Objective:
Use hot and cold water to simulate what happens when a warm front meets a cold one.

Research Questions:

What happens when a warm air mass meets a cold one?

Materials:

• Pencil and paper
• 10-gallon aquarium
• Piece of cardboard
• Scissors
• Stirrer (a wooden spoon or a ruler would be great)
• Five gallons of very cold water
• Blue food coloring
• Five gallons of very hot water
• Red food coloring
• Timer or clock
• Latex gloves
• Red colored pencil, crayon, or marker
• Blue colored pencil, crayon, or marker

Experimental Procedure

1. Use the pencil to draw seven large rectangles that look something like the aquarium on the piece of paper. Label the seven rectangles “0 minutes,” “1 minute,” “3 minutes,” “5 minutes,” “7 minutes,” “10 minutes,” and “15 minutes.”
2. Cut the piece of cardboard so that it just barely fits inside the aquarium, dividing it in half the short way. It should be very snug; it needs to keep the water on one side from mixing with the water on the other side for a minute or so. But don’t use any tape to keep it in place, it needs to come out easily!
3. With the cardboard snugly in place, fill half of the tank with the very cold water. (If it’s ice water, so much the better, but don’t get any ice in the aquarium.) Put a few drops of blue food coloring in the water and stir it; repeat as needed until you’re happy with the color. This is going to represent the cold front, or mass of cold air.
4. Now carefully fill the other half of the aquarium with very hot water and stir in some red food coloring. This is your warm front, or warm air mass.
5. Quickly draw a picture of what the tank looks like now by using the red and blue pencils to fill in the rectangle marked “0 minutes.”
6. Put on the gloves and quickly and carefully remove the sheet of cardboard. Try not to stir the water up too much in the process. Set the timer for one minute, remove the gloves, and watch what the water does until the timer rings.
7. Set the timer for two more minutes, then quickly draw a picture of what the water looked like at the one-minute mark in the rectangle labeled “1 minute.”
8. When the timer rings, set it for two more minutes and sketch what the tank looked like at the three-minute mark.
9. Repeat, setting the timer for the appropriate number of minutes (watch out, that changes toward the end) until you’ve filled in all of your rectangles.
10. Now look at your pictures. What did the “air masses” do? Did they mix right away? Was there a sharp division between them, or did the water combine and make a purple layer? Did the air masses stay side by side as they blended, or did one rise while the other sank? Why do you think the cold and warm fronts behaved the way they did?

Terms/Concepts: air mass, warm front, cold front

0

How Does Microwave Radiation Affect Different Organisms?

Grade Level: 9th to 12th; Type: Biology

Objective:

This experiment will determine how microwave radiation affects fungi, bacteria, and plant life.

Research Questions:

• Does microwave radiation destroy all life?
• Will varying lengths of radiation affect organisms differently?

Microwave ovens blast food with high levels of energy. This results in heating up certain fats and other ingredients in food. The energy simply passes through other substances without damage. Through this experiment, we will see how this energy affects simple organisms of different types.

Materials:

• Packet of radish seeds
• Paper towels
• Four small containers filled with sterilized potting soil
• Four packets of bakers’ yeast
• Four small bowls
• Four prepared Petri dishes with agar (available from biological supply companies)
• Sterilized swabs
• Gloves
• Microwave
• Notepad and pen
• Camera

Experimental Procedure

1. Plant several radish seeds in a small container. Put them in a sunny, warm location. This is the control sample.
2. Place several more radish seeds on a paper towel. Microwave the seeds for five seconds.
3. Plant these seeds in another pot and place in the same location as the control group.
4. Repeat Step 2 and 3 for two more samples, except microwave one group of seeds for fifteen seconds and the other for thirty seconds.
5. Tend the samples by watering the pots once a day and ensuring they get enough sunlight.
6. Take pictures everyday and note if and how quickly the samples grow.
7. Dump a packet of bakers’ yeast into a small bowl of warm water. Stir. This is the control sample.
8. Take note of how long it takes for the yeast to bubble up and how vigorous the reaction is. Take photos.
9. Dump another packet of bakers’ yeast onto a plate. Microwave for five seconds.
10. Mix this yeast into another bowl of warm water. Repeat Step 8.
11. Repeat steps 9 and 10 for the other packets of yeast, except microwave one sample for fifteen seconds and the other for thirty seconds.
12. Wearing gloves, use the sterilized swab to collect a sample of bacteria and swab it on a prepared Petri dish. Good places to find bacteria are areas where lots of people touch something, like doorknobs or faucets. Seal the dish and label it “control.” Put it in a warm, dark place. This is your control sample.
13. Swab another sample from the exact location as the control sample. Smear it on another Petri dish. Seal and label the dish. Place it in a warm, dark place.
14. Repeat Step 13 for the other two samples.
15. Let the samples alone overnight.
16. Take one sample out (not the control) and microwave it for five seconds. Place it back in the warm, dark place.
17. Repeat Step 16 for the other two samples, except microwave one for fifteen seconds and the other for thirty seconds.
18. After another day, take out all the samples. Note how many colonies of bacteria are growing and their size.
19. Analyze all this data. Does microwave radiation affect all life equally? Does time matter? How does each type of organism respond to the radiation?

Terms/Concepts: Microwaves, microbiology, radiation

0

Does Hair Color Affect Perception of Intelligence?

Grade Level: 6th - 9th; Type: Behavioral Science

Objective:

In this experiment, we will investigate whether hair color changes peoples' perception of intelligence.

Research Questions:

People believe in many stereotypes, such as that blondes are dumb. In this experiment, we'll change the hair color of people in photographs in order to see how it affects percpetions of intelligence.

Materials:

• Random, clear photos of people of the same race.
• Image-editing software like Adobe Photoshop
• Computer and printer
• Test subjects (the more the better)

Experimental Procedure

1. Find some random facial photos of people. Note the original color of the person's hair.
2. Open an image editing program, like Photoshop, and change the color of the person's hair to brunette, blonde, black, and red. (This guide will tell you how to do this in Photoshop: http://tutorialblog.org/photo-retouching-change-hair-color/ )
3. Remember to save a copy of the photo in each hair color.
4. Do the above for all your photos.
5. Print the photos out.
6. Ask your test subjects which person looks smarter in the series. Jot down their answer.
7. Evaluate which hair color generally got the most recognition for being “smart-looking”.

Suggested Chart

	Which Hair Color Was Said To Look the Smartest?
Series #1
Series #2
Series #3
Series #4

Terms/Concepts: Hair color; Intelligence Quotient; Perception

0

Does Chewing Gum Help You Concentrate?

Grade Level: 6th to 12th; Type: Social Science, Psychology, Health and Medicine

Objective:

This project explores whether chewing gum can help a majority of people with focus and concentration.

Research Question:

• Does chewing gum increase people’s speed and accuracy on simple cognitive tasks?

Educators have found that chewing gum can help children struggling with problems related to ADD/ADHD (Attention Deficit Disorder/Attention Deficit Hyperactivity Disorder). Is it possible that chewing gum can help all of us with focus and concentration?

 

Materials:

• Computer, printer, and paper
• Pencils for test-taking
• Chewing gum
• Timer
• Test subjects
• Paper and pencil for recording and analyzing data

Experimental Procedure

1. Write and print copies (one copy per test subject) of two simple subtraction worksheets.
2. Have subjects do each of the two worksheets. Subjects should chew gum while doing ONE of the worksheets.
3. Record how long it took each subject to complete each worksheet.
4. Score the worksheets for number of problems correct.
5. Analyze your results. Did chewing gum increase people’s speed and accuracy on subtraction tests?
6. Try the experiment in different environments, with different test subjects, and under different circumstances, keeping in mind these questions and any others that come up in the course of your research:
   • Does chewing gum make more of a difference in certain environments (e.g. noisy, crowded, or otherwise distracting environments)?
   • Does chewing gum make more of a difference to people of certain ages or genders?
   • Does chewing gum make more of a difference at certain times of day (e.g. early morning or late afternoon)?
   • Does chewing gum make more of a difference before or after certain activities (e.g. just before lunchtime or after physical exercise)?

Terms/Concepts: chewing gum, concentration, focus, ADD, ADHD

0

how to Turn Hand Warmers into Hot Ice Sculpture

Grade Level: 7th to 9th; Type: Chemistry

Objective:

This experiment provides a graphic illustration of the chemical reaction that transpires when you activate a hand warmer.

Research Questions:

• What is in hand warmers?
• How do hand warmers work?
• Why does the “hot ice” form in thie experiment?

Hand warmers provide instant heat on a cold day. They're also useful for making sculpture!

 

Materials:

• Five Reusable Hand Warmers
• Scissors
• Plate
• Bottle

Experimental Procedure

1. Activate one of the hand warmers.
2. When it turns white and stops giving off heat, cut it open and remove a single crystal.
3. Place the crystal on a plate.
4. Cut open the other four hand warmers and pour their contents into the bottle.
5. Carefully pour the contents of the bottle onto the crystal. Watch the effect. Voila! You are a modern artist!

Terms/Concepts: exothermic, endothermic, chemical instances

0

Vegetable Power

Grade Level: 6th - 9th; Type: Physical Science
To see if an LED light can be powered by vegetables and/or fruits.
The purpose of this experiment is to determine whether there is enough energy stored in a fruit or a vegetable to power an LED light. This experiment can be taken further to determine how long a fruit or vegetable can power an LED for.

• How is energy stored in a fruit or vegetable?
• How to we measure this type of energy?
• How do we usually use the energy stored in plants?
• Where do plants get their energy from?
• How much energy is stored in a typical potato?
• How much energy is stored in the other fruits or vegetables you are using?

With the help of a few household items, a potato can be used to power a light bulb. All living organisms contain energy and it may be possible to tap into and use some of that energy in our everyday lives. Given that our main source of energy, fossil fuel, is in limited supply, it is important for scientists to explore the use of alternative energy sources. Many natural, green energies are already being used around the world, but there is still a lot to learn about utilizing alternative energy sources. By developing planet-friendly ways to draw energy from the world around us, we can decrease our use of polluting energy sources which will help keep the air, water and soil clean for future generations.

• LED light bulb
• Assorted fresh fruits and vegetables (i.e. carrot, apple, pear, squash, lemon)
• 1 potato
• 1 shiny penny
• 1 galvanized steel nail
• 2 eight inch lengths of copper wire
• A knife

The materials needed for this experiment can be found at the grocery store and at the hardware store.

:

1. Begin by constructing a potato light. We already know that potatoes can be used to power LED lights, and setting up a working light in a potato will help you determine whether you are constructing the vegetable powered light correctly.
2. Make an incision in one side of the potato just large enough for the penny to fit inside.
3. Wrap one end of a piece of copper wire around the penny.
4. Wrap one end of another piece of copper wire around the nail.
5. Insert the penny into the slit you created for it, with the loose end of wire hanging out.
6. Insert the nail into the other side of the potato with the loose end of wire hanging out.
7. Do not allow the penny and nail to touch.
8. Wrap the copper wire coming off the penny to the longer leg of the LED.
9. Wrap the copper wire coming off the nail to the short leg of the LED.
10. Observe the results.
11. Repeat steps 2-10 with other vegetables or fruits.

Terms/Concepts: Green energy; Fossil fuel; Alternative energy; Potential energy; Filament; LED light

0

How To Do Flame Tests

Flame Test Introduction

The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color the salt turns the flame of a Bunsen burner. The heat of the flame excites the electrons of the metals ions, causing them to emit visible light. Every element has a signature emission spectrum that can be used to differentiate between one element and another.

How to Do the Flame Test

Classic Wire Loop Method
First, you need a clean wire loop. Platinum or nickel-chromium loops are most common. They may be cleaned by dipping in hydrochloric or nitric acid, followed by rinsing with distilled or deionized water. Test the cleanliness of the loop by inserting it into a gas flame.

If a burst of color is produced, the loop is not sufficiently clean. The loop must be cleaned between tests.

The clean loop is dipped in either a powder or solution of an ionic (metal) salt. The loop with sample is placed in the clear or blue part of the flame and the resulting color is observed.
Wooden Splint or Cotton Swab Method
Wooden splints or cotton swabs offer an inexpensive alternative to wire loops. To use wooden splints, soak them overnight in distilled water. Pour out the water and rinse the splints with clean water, being careful to avoid contaminating the water with sodium (as from sweat on your hands). Take a damp splint or cotton swab that has been moistened in water, dip it in the sample to be tested, and wave the splint or swab through the flame.

Do not hold the sample in the flame as this would cause the splint or swab to ignite. Use a new splint or swab for each test.

How to Interpret Flame Test Results

The sample is identified by comparing the observed flame color against known values from a table or chart.
Red
Carmine to Magenta: Lithium compounds.

Masked by barium or sodium.
Scarlet or Crimson: Strontium compounds. Masked by barium.
Red: Rubidium (unfiltered flame)
Yellow-Red: Calcium compounds. Masked by barium.

Yellow
Gold: Iron
Intense Yellow: Sodium compounds, even in trace amounts. A yellow flame is not indicative of sodium unless it persists and is not intensified by addition of 1% NaCl to the dry compound.
White
Bright White: Magnesium
White-Green: Zinc
Green
Emerald: Copper compounds, other than halides. Thallium.
Bright Green: Boron
Blue-Green: Phosphates, when moistened with H₂SO₄ or B₂O₃.
Faint Green: Antimony and NH₄ compounds.
Yellow-Green: Barium, manganese(II), molybdenum.
Blue
Azure: Lead, selenium, bismuth, cesium, copper(I), CuCl₂ and other copper compounds moistened with hydrochloric acid, indium, lead.
Light Blue: Arsenic and come of its compounds.
Greenish Blue: CuBr₂, antimony
Purple
Violet: Potassium compounds other than borates, phosphates, and silicates. Masked by sodium or lithium.
Lilac to Purple-Red: Potassium, rubidium, and/or cesium in the presence of sodium when viewed through a blue glass.

Limitations of the Flame Test

• The test cannot detect low concentrations of most ions.
• The brightness of the signal varies from one sample to another. For example, the yellow emission from sodium is much brighter than the red emission from the same amount of lithium.
• Impurities or contaminants affect the test results. Sodium, in particular, is present in most compounds and will color the flame. Sometimes a blue glass is used to filter out the yellow of sodium.
• The test cannot differentiate between all elements. Several metals produce the same flame color. Some compounds do not change the color of the flame at all.

Primary Reference: Lange's Handbook of Chemistry, 8th Edition, Handbook Publishers Inc., 1952.

Flame Test Colors

Symbol	Element	Color
As	Arsenic	Blue
B	Boron	Bright green
Ba	Barium	Pale/Yellowish Green
Ca	Calcium	Orange to red
Cs	Cesium	Blue
Cu(I	Copper(I)	Blue
Cu(II)	Copper(II) non-halide	Green
Cu(II)	Copper(II) halide	Blue-green
Fe	Iron	Gold
In	Indium	Blue
K	Potassium	Lilac to red
Li	Lithium	Magenta to carmine
Mg	Magnesium	Bright white
Mn(II)	Manganese(II)	Yellowish green
Mo	Molybdenum	Yellowish green
Na	Sodium	Intense yellow
P	Phosphorus	Pale bluish green
Pb	Lead	Blue
Rb	Rubidium	Red to purple-red
Sb	Antimony	Pale green
Se	Selenium	Azure blue
Sr	Strontium	Crimson
Te	Tellurium	Pale green
Tl	Thallium	Pure green
Zn	Zinc	Bluish green to whitish green

0

How Fires Burn in Different Colors

Grade Level: 7th to 9th; Type: Chemistry

Objective:

In this experiment you will observe fire burning in different colors.

Research Questions:

• Why do you think each fire burns a different color?
• Which color do you think is the hottest?
• Which color do you think is the coldest?

Materials:

• Menthol
• Epsom salt (Magnesium Sulfate)
• No salt - salt substitute (potassium chloride/bitartrate)
• Borax (boric acid)
• Bowl
• Lighter torch

Experimental Procedure

• WHITE

1. Pour 1/4 cup of magnesium sulfate into the bowl.
2. Pour 1/2 cup of the menthol into the bowl.
3. Light the mixture with the lighter torch.
4. Observe.

• BLUE VIOLET

1. Pour 1/4 cup of potassium chloride/bitartrate into the bowl.
2. Pour 1/2 cup of menthol into the bowl.
3. Light the mixture with the lighter torch.
4. Observe.

• GREEN

1. Pour 1/4 cup of boric acid into the bowl.
2. Pour 1/2 cup of menthol into the bowl.
3. Light the mixture with the lighter torch.
4. Observe.

Terms/Concepts: flame test, elements
References: Flame Tests:  How To Do Flame Tests

0