Soil Density and pH
Third grade Earth Science lesson
Liaison: Adam Cohen
Date: 04/28/00
Group Members: Deb Eisner and Kate Hable
School: Agassiz
Teacher: Ms. Payson
Materials:
sand
dense dirt
humus
sifter
bowl
water paper cups
red cabbage
celery
food coloring
Procedure:
1. Series of questions to introduce topic: Where do
seeds live? What would help them stay in place? Where
does their food come from? etc.
2. Show how three different types of "soils" compare
for best seed life. Use sand, dense dirt, and humus.
Put each in a sifter and watch how much goes through.
Then pour water through and see how much washes away.
3. Introduce acids and bases. Explain what is best for
plants and why different soils have different ph's.
4. Distribute soil sample to each student. Pour water
into sample until there is a little bit on top of the
sample.
5. Using mushed up red cabbage as the indicator, test
the pH of the soil samples.
6. Discuss conclusions.
7. Prep. for next weeks lesson on water transport and
photosynthesis. Place celery in a cup of water with
food coloring in it. Leave for kids to see later that
the celery "drank" the water and is changing to the
color of the food coloring.
Evaluation:
Comments:
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