Initiatives

Science, Technology, Engineering & Math (STEM) Challenge Question of the Month

Our monthly STEM contest is brought to you by Girl Scouts in collaboration with Louisiana Children's Museum. Winning troops (one per age level) will receive a troop camping voucher and your troop will be able to camp for free* at Camp Whispering Pines!

Congratulations to Brownie troop 1451 for answering February's contest and winning troop camping vouchers. Deadline for the March contest is April 18. Click here for rules. Remember to submit you answers along with your Troop # and age level, as well as Leader’s name and contact information.

Check out the Louisiana Children's Museum's upcoming Super Science Saturday on April 5, 2008,  11 a.m. – 3 p.m. Open to the public with museum admission. Explore dinosaur worlds from the Jurassic and Cretaceous. Roam the vast halls careful to avoid the meat eating 10 foot tall mega raptor. Look out for the sharp teeth of the 5 foot t-rex skull. Puzzle at how to put together a duckbill dinosaur’s real leg bone. Dig up dinosaurs in the sand, touch real dino bones, stencil and paint their huge skulls. Drill and find an oil field in the fun filled Gulf of Mexico oil finder game.

It’s your turn to become a detective and conduct the experiments you've seen on TV! Complete these forensic experiments to come closer to closing the case.

Brownie Girl Scout Question: Ink Identification

A ransom note is important evidence in the theft of a bicycle. If forensic investigators can identify the pen that wrote the note, they may be able to link a note to the suspect. Try the following activity to investigate one way to identify ink and the pen it came from.

Materials:

Scissors, coffee filters, ruler, drinking glass, tap water, paper towel, a variety of water soluble felt-tipped pens

Procedure:

  1. Cut the coffee filters into several 1 inch strips.
  2. Make a thick circle with one felt-tipped pen about 1 inch from the end of the strip.
  3. Pour water into the drinking glass so that it fills ½ inch of the bottom of the glass.
  4. Dip the end of the strip in the water so that the water covers about ½ inch of the end of the strip that you marked. The water should not touch the circle you drew.
  5. Watch the water creep up the strip until it reaches the top of the strip.
  6. Take the strip out of the water and place it on the paper towel. Above the filter, write the name of the color of the pen on the paper towel, using the same pen you used on the strip.
  7. Repeat the experiment with the rest of the strips and pens.
  8. Observe what happened to the circles made on the strips. What do you notice about the dyes in the pens? 

You performed an ink chromatography test.

Junior Girl Scout Question: Blood Identification

A few drops of a red substance are found at the house of a missing dog. Are the drops red paint, ketchup, or possible blood? The identification of the substance is important and will help a detective know which way to direct an investigation. Try the following activity to identify the red substance.

Materials: eyedropper, red watercolor paint, ketchup, blood from a meat tray, plate, tap water, Hemastix (available at most drugstores).

Procedure:

  1. Use the eyedropper to place 1 drop of red paint, 1 drop of ketchup, and 1 drop of blood on the plate.
  2. Add a drop of water to each red drop to make sure that they do not dry out.
  3. Put a Hemastix strip in each solution. What happens? What color does the Hemastix strip turn in each solution? What color indicates blood? Record your findings.

Cadette Girl Scout Question: Mystery Substances

Any unknown substance found at a crime scene may be important evidence. The liquid left in a drinking glass might be a poison, or residue found on a suspect’s hand may be gunpowder. As you know, forensic chemists perform many tests on unknown substances in order to identify them. Color, odor, and reaction to other substances are all clues to identify an unknown substance. Try the following activity to perform another important test.

Materials: 1 ½ quarts tap water, 2 quart saucepan, 2 red cabbage leaves, timer, colander, plastic bowl, marking pen, masking tape, 5 glasses, measuring cup, 3 tablespoons of concentrated lemon juice, 3 tablespoons of vinegar, 3 tablespoons of distilled water, 1 tablespoon of baking soda, 3 tablespoons of ammonia, pencil, sheet of white paper

Procedure:

  1. Put the water in the saucepan. Tear the red cabbage leaves into small pieces and place them in the water.
  2. Have your adult helper heat the water to boiling and boil the leaves for 5 minutes. All the liquid to cool.
  3. Hold the colander over the bowl and have an adult help you to carefully strain the leaves through the colander. Throw the leaves away.
  4. use the marking pen and masking tape to label the glasses from 1 to 5.
  5. Pour about ½ cup of the cabbage juice into each jar.
  6. Add the lemon juice to jar1, the vinegar to jar 2, the distilled water to jar 3, the baking soda to jar 4, and the ammonia to jar 5.
  7. Observe the color that each substance turns the cabbage juice, and record the color on a chart.

Cabbage juice is a chemical indicator that changes color in the presence of an acid or a base. If the substance is an acid, the cabbage juice turns red. If the substance is a base, the juice turns green.

Senior Girl Scout Question:

Even a note that has been completely burned can be important evidence in an investigation. Try the following activity to restore and read a burned document.

Materials: ballpoint pen, white paper, metal pan, matches, cookie sheet, ½ cup glycerin, 1 ½ cups tap water, spray bottle.

Procedure:

  1. Write a message on the white paper.
  2. Crumple the paper into a ball and place it in the middle of the metal pan.
  3. Have an adult use the matches to set the paper on fire.
  4. Allow the fire to burn out and cool down. When the burned paper is cool, carefully transfer it to the cookie sheet.
  5. Observe the burned paper. Can you still see any of the writing on the paper?
  6. Mix the glycerin with the water and place the mixture in the spray bottle.
  7. Carefully spray the burned paper with the mixture until the paper is completely wet. Gently unfold the crumpled paper and flatten it on the cookie sheet.
  8. Observe the paper. Can you read any of the writing?

Handling a burned document is one of the most difficult tasks a crime lab can face. The forensic scientist must first flatten the burned document with causing it to fall apart. Then, they float the burned sheets in a large tray containing a mixture of glycerin, alcohol, and a chemical called choral hydrate to soften the paper. Once the document is flattened, the scientists try to read it. Most ballpoint pen inks contain a small amount of metal in the dyes. These metals are able to survive fire, so anything written with a ballpoint pen can be seen when the paper is flattened.

*Rules to participate: 1) No emails will be accepted; 2) All submissions must include service unit and troop number, troop leaders and girls’ names; 3) All camping is based upon availability and leaders must be trained; 4) Only camping fees are waived; All other fees (i.e. lifeguards, boating, etc.) are not included.

Mail, fax or drop off your troop’s answer by April 18, to Girl Scout Council of Southeast Louisiana, Attn: STEM, 841 S. Clearview Parkway, New Orleans, LA 70121, Fax: (504) 733-8219.