Rocks Day 2
Pieces of rocks
Materials:
Brick fragments marked with number in sharpie pen
Water
clear plastic sheets
2 Plastic gallon jars
Sauk River pictures
Screens
River rocks, sand,
gravel
Tubs
Lesson
Rocks change
Show pictures of hike on river.
Show the kids the rocks, sand, gravel.
Why the different sizes?
Do they look the same?
Have them use screens to sort the various sizes.
Look at the ocean sand. It is even finer than the river sand.
Why?
Show gravel. Is it from the same source? How can you tell?
The gravel had sharp edges, the river rocks didn’t. Why? Look
at pictures again.
Watch Magic School Bus Rocks and Rolls, perhaps just the
segment on the bottom of the river.
Set up experiment to see if we can make rocks smooth.
What ingredients would we need to simulate river?
How can we make movement like river.
2. Put 6-10 angular fragments in the quart jar and add enough
water to fill halfway. Fasten the lid tightly.
3. Ask 10 students to give the jar 100 shakes each.
4. After 1000 shakes, let the students examine the fragments
and observe the color of the water. Pour the water into the
gallon jar and let the sediment settle.
1. Trace the fragments onto clear plastic sheet. Each day, after
shaking, trace again on new sheet and overlay. Have they
changed size?
Notebook
How could we speed up the change?
2. Add some sand to the fragments and water to see if this
speeds up the process. Use one jar with just fragments and
water as a control and to the second jar add a cup of coarse
sand. Follow the same procedure and keep a record of the
results.
How separate different sized pieces? Let students suggest using
the screens.
If time:
1.
2.
3.
4.
5.
Can the children think of other ways that rocks are
different besides their size and color?
Show several rocks. Tell them today we will find out
which rocks are the heaviest.
Have the children try to tell by first looking and then by
feeling which rock will be the heaviest and which one
will be the lightest.
Have the children take turns putting two rocks at a time
in the balance scale to see which rock is the heaviest.
They then draw a picture of a light rock and a heavy
rock in their notebooks.
Comments:
Follow up this activity by asking if the rock they thought would
be the heaviest was in fact the heaviest. Also, is the biggest rock
always the heaviest?
Have students write in
notebooks what they
learned today.