Heat = Energy = Particles Move Faster and Further away from each other Review: Big Idea 1 Heat = Energy = Particles Move Faster and Further away from each other

Review Big idea 2 Diffusion- when particles in nature tend to spread out and move away from each other

Today’s Question How does nature Sort out Particles? Model of a River- What order do you think it will settle? Wood chips Large rocks Small rocks Dirt Model River sticks- Which particles sorted on the bottom? Middle? Top? Did this match your guess?

Video River Clips http://faculty.gg.uwyo.edu/heller/SedMovs/Dietrich.htm http://www.youtube.com/watch?v=O9GVRKnMch8&feature=related Questions 1. What sized particles moved the most? 2. Which particles didn’t move very well or at all? 3. Which moved the fastest? Slowest? 4. What sized particles did you notice at the top of the river? 5. What sized particles were at the bottom of the river? 6. Some large white rocks moved w/out a problem even though they were bigger than some of the black rocks. What other factors besides size might affect rock sorting?

Animations and Videos http://www.classzone.com/books/earth_science/terc/content/visualizations/es0604/es0604page01.cfm?chapter_no=visualization Animation Notes: Draw a Picture of the animation Explain: As the river slows down the larger-MORE DENSE particles settle first, until the river is it’s slowest and enters the lake. Then all the less dense particles settle

Today’s Big Idea Nature Sorts natural particles by Density and by Size! The more dense items are always on the bottom, or settled first, then the less dense items. The larger items also usually settle first, or are at the bottom

Order of materials Wood chips/ bark Silt Sand Pebbles Rock In a river bed silt travels the farthest Rocks travel the least