1. Sorting of Earth’s Materials: Beaches, Streams and Road Cuts.

2. What is Sorting?
Sorting is arranging things according to class, kind, or size; classify.
Density affects the sorting of natural materials in a mixture.

3. Jar Activity Before Shaking/Mixing What do you observe? After

4. Sorting in General
Density affects the sorting of naturally occurring materials in a mixture.
For example, in the stream to the right, dense objects like heavy and large rocks stay at the bottom while less dense objects like light and small silt and dirt can be carried away by the flow.  

5. What is density? Density = Mass/Volume
Mass = The amount of matter in something.
Volume = The amount of space occupied by something. It is the size of something.

6. How does density affect sorting?
Knowing that some things float while others sink gives us a good idea about how density relates to things around us. Not only does density determine when something will sink, it also is responsible for the different layers of the Earth and the sorting of natural materials on the Earth!

7. How does density affect sorting?
Below you will find photographs to represent the different layers of the Earth. At the right of each photograph you will find the density for that layer. What layer would each of these objects represent based on the density given. B A
Density = g/cm3
Density =
Close to 2.7 to 3 g/cm3
Density = 1 g/cm3
Density
4.5 g/cm3 D C
Density = 11.5 – 13.0 g/cm3 E

8. Does particle size affect sorting?
Does the size of particles matter in how they will sort in a river, road cut and beach?
Have you ever heard the saying “the bigger they are the harder they fall”?
Large particles are often more heavy and difficult to move just because of overall size. The large particles may in fact be less dense per cm3 than smaller particles that get washed away in a river. However, because of overall size they don’t move as easily.
Robert Wadlow
( ) holds the record for the world's tallest person at 8 feet 11.1 inches tall. The tallest living person is Sultan Kosen of Turkey, at 8 feet 1 inch tall.

9. How will Earth particles made with the SAME MATERIAL or Matter but different sizes sort?
Below are pictures of six different-sized particles of rock that are made of the same basic stuff that could be found on Earth. Imagine that you put them in a large container filled with water and then shake the container vigorously to model sorting of a river. The particles are labeled A, B, C, D,  E and F. Which particle would go to the bottom 1st? 2nd? 3rd? ……. Why?

10. How will Earth particles made with the DIFFERENT MATERIALS or Matter but EQUAL sizes sort?
Do you remember our 4 – Color Column Demonstration? Will Earth materials do the same when mixed up?
Clear Air (gas) g/cm3 Density
Yellow Fluid 0.93g/cm3 Density
Green Fluid 1.01g/cm3 Density
Red Fluid 1.38g/cm3 Density

11. Imagine if …..
Sand Origins
Imagine if you traveled around the world and collected sand samples from different beaches that you visited. The sand grains you collect end up being roughly the same size.
Does this mean that the density of the sand grains will also be the same?
How will the sand of different types/densities sort if placed in a jar and shaken up?

12. Sorting according to density in Nature
Can you think of any examples of sorting by density and/or size in nature?
Beaches
Streams
Road Cut

13. Sorting: The Beach
Have you ever walked along a beach and wondered why the sand particles are all in one basic area and the grains are all about the same size?

14. Sorting: Stream or River
Try and think of the rocks you have observed in a river or stream. Why do you not see small sized and low density particles like sand and silt being deposited in fast moving water? Why are the big rocks staying in place?

15. Action of Streams
Tubing Story

16. Road Cuts

17. Quiz a. rock, sand, water, metal b. metal, rock, sand, water
Pat puts items into a jar and shakes it up. Pat lets the jar settle for 5 minutes. What would be the expected order of the items going from the top of the container to the bottom?
a. rock, sand, water, metal
b. metal, rock, sand, water
c. water, sand, rock, metal
d. sand, metal, water, rock

18. Quiz
A streambed contains round rocks, all about the same size. Why are there no smaller particles of sand and clay? The sand and clay…
A.  are too small to see  
B.  are denser  
C.  have washed away  
D.  were never there

19. Quiz
A beach is composed of particles of sand of the same size. Why doesn't the beach have materials of all sizes? The particles have…
A.  been placed there by humans 
B.  come to the beach at the same time.  
C.  been found in underwater canyons  
D.  been sorted by size and density

20. Quiz
Sand with particles of the same size was gently shaken in a jar to see if layers would form. What variable was being tested?
A.  particle size  
B.  particle density  
C.  particle color  
D.  particle type

21. Quiz
Where would the smallest particles of rock be deposited in a streambed?
a. Where the water is moving the fastest
b. Where the water is moving the slowest
c. Near the middle
d. At the beginning

22. Quiz
In an experiment, students shook jars of water with soil and rock in them. What could the shaking model in nature?
a. A lake environment
b. A stream current
c. Living things in an environment
d. A rainstorm

23. Quiz
A student shakes a jar with a mixture of sand types. Instead of mixing, the sand grains separate into layers. Why?
a. The grains are different colors.
b. The grains have different shapes.
c. The grains have different densities.
d. The jar has a round shape.

24. Quiz
In the spring, rivers in Utah are cloudy or murky. A sample of the water shows it contains very small particles of silt. Why is silt suspended in the water?
a. The water is moving rapidly.
b. Silt is small with low density.
Water has a high density