April 2012
2nd Grade: Unit- Soil
Duration: 45 Minutes
Title: Soils Settling in Water
Materials: 1 small container of clay, 1 sand, 1 humus, 1 cup of water, 3 tubes – container to
hold up dropper, 1 dropper, tray
Resources: Teacher’s Guide on soil
Objective: The students will be able to discuss what happens when sand, clay, and humus settle
in water
Procedures:
I.
II.
III.
Opening (1:50-2:05)
a. Go over the three main components of soil
b. Sand: small grains of crushed rock, chalky
c. Clay: very small grains, orange
d. Humus: like soil, decomposing plants and insects
e. Now we are going to do an experiment on what happens when the different
components are mixed with water
Activity (2:00-2:25)
a. Remember – scientific method
b. Question: How will sand, clay, and hummus settle in water?
c. Hypothesis: Have them individually make observations on what they think will
happen when I put water in to the tube
d. Have the students watch me pour sand, humus, and clay into each of the tubes
e. Ask, what are our materials?
f. Procedure: Give them. Ask them what to do next.
g. Read reading on sand and clay if the tubes need time to settle (can put in cups to
keep upright)
h. Results: have them write on their paper what happened for each material
i. Describe why each component settled the way it did, ask if they have any idea,
use examples: throw a rock in water what happens? Etc.
Closing/Wrap-Up (2:20-2:30)
a. Next week we will observe the differences between sand, clay and humus when
they are wet.
Student Assessment: Collect the papers. Still time? Do the reading on clay and brick. Have them
brainstorm what they could make with clay.
Teacher Notes:
1 small container of clay, 1 sand, 1 humus, 1 cup of water
3 tubes – container to hold up dropper
1 dropper
tray
The larger the particle, the quicker it falls – larger particles reach the bottom first and form the
lowest layer, next largest form the next later and so on. Settling provides an easy way to
separate soil on the basis of particular size
Sand – does separate by particle size but it happens so quickly that it is hard to see
Clay – particles are smaller and remain suspended longer, settling easily reveals their size
differences
TEST - is clay present in the soil?
-
Clay turns all the water the same color as the clay
After 10min – the largest particles of the clay have settled on the bottom with clear water above