9 th Grade Lesson 42 Prep Work. Plug in the Lava Lamp the day before.

Transcription

1 9 th Grade Lesson 42 Prep Work Plug in the Lava Lamp the day before.

2 Lesson 42 9 th Grade * Earth Science Mr. Petersen Bonneville Junior High Granite School District

3 Self Starter * 40 Points * 11/5/2014 * Lesson 42 Today s Learning Objective and Questions Write Everything * Don t Abbreviate or shorten this assignment Today s Learning Objective: Students will evaluate the source of Earth s internal heat. Essential Question: How do scientists use the Hertzsprung-Russel Diagram? Answer: Tool astronomers use to classify stars according to their luminosity, spectral type, color, temperature and evolutionary stage. Homework: Study for the SAGE Test Lessons 1-38.

4 Glossary Portfolio 3 [ 1] 1. Solar Wind- 2. Tides- 3. Heavy Elements- 4. Milky Way 5. Inference- 6. Chromosphere- 7. Jovian Planet- 8. Terrestrial Planet- 9. Heat 10. Atmosphere- 11. Light Year- 12. Radioactive Dating- 13. Law of Superposition- 14. Chemosynthesis- 15. Heliocentric- 16. H-R Diagram 17. Radioactivity (radioactive decay)-

5 Standard 2, Objective 1 Evaluate the source of Earth s internal heat and the evidence of Earth s internal structure.

6 Earth s Internal Heat If you think about a volcano, you know Earth must be hot inside. The heat inside Earth moves continents, builds mountains and causes earthquakes. Where does all this heat inside Earth come from?

7 Call on 5 Student To Read

8 Reader 1 Earth was hot when it formed. A lot of Earth s heat is leftover from when our planet formed, four-and-a-half billion years ago. Earth is thought to have arisen from a cloud of gas and dust in space. Solid particles, called planetesimals condensed out of the cloud. They re thought to have stuck together and created the early Earth. Bombarding planetesimals heated Earth to a molten state. So Earth started out with a lot of heat.

9 Reader 2 Earth makes some of its own heat. Earth is cooling now but very, very slowly. Earth is close to a steady temperature state. Over the past several billion years, it might have cooled a couple of hundred degrees. Earth keeps a nearly steady temperature, because it makes heat in its interior.

10 Reader 3 In other words, Earth has been losing heat since it formed, billions of years ago. But it s producing almost as much heat as it is losing. The process by which Earth makes heat is called radioactive decay. It involves the disintegration of natural radioactive elements inside Earth like uranium, for example. Uranium is a special kind of element because when it decays, heat is produced. It s this heat that keeps Earth from cooling off completely.

11 Reader 4 Many of the rocks in Earth s crust and interior undergo this process of radioactive decay. This process produces subatomic particles that zip away, and later collide with surrounding material inside the Earth. Their energy of motion is converted to heat.

12 Reader 5 Without this process of radioactive decay, there would be fewer volcanoes and earthquakes and less building of Earth s vast mountain ranges.

13 Main Point! Radioactive Decay keeps the earth warm.

14 There are 2 things given off during radioactive decay.

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17 Radiation vs Radioactive Atoms * 3:00

18 Teacher Read The energy that is created by radioactive decay in the earth is used to operate the process of convection.

19 Demonstration Observe the lava lamp.

20 Understanding Convection What cause the color globs of oil to move up? The heat up and the molecules on the color oil move farther apart. This cause the oil to be lighter than the surrounding oil. Light materials move over heavier materials. What cause the color globs of oil to move down? The color oil cools and becomes more dense. The more dense oil is heavier so it sinks to the bottom.

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22 Convection Convection happens with the following fluid like materials: Water Air Magma inside the earth. Remember the saying: Hot air rises! Cold air sinks.

23 Re-teach 1. Is the earth now cooling or heating up? It is slowly cooling down 2. What causes the heat inside the earth? Radioactivity or radioactive decay 3. What type of radiation do we have to worry about and why do we have the worry about this type of radiation? Gamma Rays because it can t be stopped as easily. 4. What happens to molecules when they are heated? They become less dense or move farther apart from each other.

24 Re-Teach 5. List three fluid materials convection can happen in. Air, Water and Magma (any liquid) 6. What 2 things are given of during radioactive decay? energy and a particle 7. What is the saying you have to remember about convection? Hot air rises and cold air sinks.

25 16 points Use a sheet of paper

26 Constructive Response Assessment 1. What causes the heat inside the earth? 2. What type of radiation do we have to worry about and why do we have to worry about this type of radiation? 3. What happens to molecules when they are heated?

27 Constructive Response Assessment 4. List three fluid materials convection can happen in. 5. What 2 things are given of during radioactive decay? 6. What is the saying you have to remember about convection?

28 Constructive Response Assessment 7. Draw two boxes. Show one box with a flame underneath it and show what the molecules would look like inside this box. Show the second box without a flame. Draw what the same molecules would look like in this box. 8. Is the earth heating up or cooling down?

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