The Case of the Terrible T. Rex (10 page)
Now all you have to do is compare the color of your fish to the pH chart below. Determine which of the water samples were acids, bases, or neutrals. Were your fish swimming in “clean” or polluted water? Gadzooks! It’s up to you to save the day! There’s no time to lose!
*For this exercise, we will assume that anything other than a neutral pH indicates polluted water. In nature, this is not always the case.
For a full color pH scale, visit
http://commons.wikimedia.org/wiki/File:PH_scale.png
BE A REAL-LIFE HERO!
Face it. Fish and other aquatic wildlife depend on us to keep their habitat clean. Why not be a real-life hero and help out your local waterway? Your efforts could save hundreds, maybe thousands, of lives! Here are some resources to get you started:
•
www.kidsforsavingearth.org/waterpollution/waterpollution.htm
•
www.epa.gov/adopt/earthday/index.html
•
www.kiddyhouse.com/Themes/Environ/Water.html
•
www.oceansidecleanwaterprogram.org/kids.asp
I
n 1979, thirteen-year-old India Wood saw a bone sticking out of some layers of rock in Colorado. Being an amateur fossil hunter, India carefully excavated the bone. She identified it as the pelvic bone of an
Allosaurus
, a carnivorous dinosaur. Over the next several years, and with some help from the Denver Museum of Nature & Science, India excavated the entire
Allosaurus
skeleton (now on display at the museum). Way to go, India!
In this activity, not only will you create your own cool sedimentary layers, but you’ll also practice digging for dinosaurs, just like India did!
MATERIALS
• 2-quart container with tight lid
• playground sand
• measuring spoons
• food coloring: green, yellow, blue, and red
• small plastic aquarium or similar clear container, approximately 11 by 7 by 8 inches (you can do an Internet search for “Critter Keeper”)
• 8 to 10 small “fossils,” such as shells, chicken bones (make sure they're clean!), or plastic dinosaurs
• small, clean paintbrush
PROCEDURE
1.
Fill the 2-quart container about ⅔ full of sand.
2.
Add 1½ teaspoons of green food coloring to the sand.
3.
Replace the lid on the container and shake the sand for about 1 minute until the sand turns green.
4.
Pour half of the green sand into the plastic aquarium. Place some of your fossils here and there on the sand, and then pour in the remaining green sand.
5.
Repeat steps 1–4 with each of the yellow, blue, and red food colorings.
6.
Record your observations. (Can you see the different stratification layers?)
7.
Using the paintbrush, go on a dig. Carefully brush away the sand until you—
gasp!
—stumble upon a fossil! Continue to brush away the excess sand until the fossil is completely exposed. (If you need to scoop out some sand from your aquarium, go ahead. Just be sure you don’t disturb or remove your amazing fossil.)
8.
Draw a site map in your notebook.
Tip:
Looking down from above, draw a picture of your fossil exactly where it lies. Label your fossil and indicate what color layer you found it in.
