This CNNfyi.com lesson plan is supplemented with material from

Big extinction

March 28, 2001
Web posted at: 6:24 PM EST (2324 GMT)

Editor's note: CNNfyi.com updates its page at 1 a.m. EST. Users can find stories from the previous five days under MORE STORIES/LESSON PLANS and under the Subject Areas archives.

For the best possible presentation of this story, also use the video version from today's CNN NEWSROOM broadcast. Have students compare the video version to the Web news story. Ask: Do you discover different perceptions about the topic from one story to another? Which did you prefer in this case, and why?

After students read the CNNfyi.com article, "The second big bang," ask the following:

1. What evidence was recently found of a pre-dinosaur era meteoric collision? What were the most "famous" living creatures at that time? How do we know about them? About how many species existed on Earth at that time? What is thought to have happened to most of those species as a result of the asteroid collision? What was the process that brought about their deaths? About what percentage of all living species are thought to have survived the aftereffects of the impact? How did the percentage of fish surviving compare to the overall survival rate? Why do you think this is so?

2. Why would the presence of buckminsterfullerenes -- or buckyball -- molecules indicate that there was a meteoric impact? What is trapped inside the molecules? How do you think scientists were able to extract the gas? About how often do scientists believe an impact of this kind occurs on Earth? What do you think could be done to prevent a future impact, given 10 to 100 years advance notice?

3. Have your students learn more about the gas carrier molecules mentioned in this story, buckminsterfullerines (buckyballs), through building a buckyball molecule model. Discuss the following information with the class:

• C60 Buckyball molecules are made of 60 carbon atoms, all attached to one another to form a hollow, spherical ball.
• The 60 carbon atoms form a shape called a truncated icosahedron, which looks essentially like a soccer ball. It consists of 12 regular pentagons (five-sided figure) and 20 regular hexagons (six-sided figure).
• The C60 molecule does not easily bond to other atoms or molecules, because all of its atoms are already bonded to make the carbon atom "ball".

4. Divide the class into small groups. Provide each group with sixty small marshmallows, one box of toothpicks and a soccer ball. Explain that the marshmallows represent carbon atoms and that the toothpicks represent the bonds attaching the carbon atoms to one another. Instruct students to build their model, remembering that it should be made of 12 regular pentagons and 20 regular hexagons, organized in any way they wish, to form a hollow ball. Suggest that they refer to the soccer ball for a visual guide to get them started.

5. Have all groups share their models, and explain how they think gasses enter the buckyballs and why some gasses remain trapped inside them for many years. Then, have students investigate the reference sites below and learn how leading scientists believe the gasses became trapped.

For additional information, read Harcourt College's article, A Permian impact?

Outer space gas trapped on Earth in 'buckyballs'
March 22, 2000

Inflating buckyballs with noble gases.
Buckyballs

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