Goal(s): Students will complete a variety of activities that demonstrate how weathering and erosion change the Earth’s surface.
Grade level(s): 4-5
Students will be able to identify and explain (in at least one way) how weathering and erosion changes the Earth’s surface.
15 rough, sandstone, limestone, or shale rocks (1 set X four groups)
Three 32 ounce plastic containers (1 set X four groups)
Three jars (1 set X four groups)
pen, paper, and masking tape, to label both the containers and the clear jars with A, B, C
small plastic trays (1 for each group)
magnifying glasses (2 for each group)
water (16 ounces per group)
Time Allotment: 1 class period, 15 minutes of prep time the day before
Vocabulary: weathering, erosion, sediment, environmental elements
What happened when the rocks were exposed to water?
What happened when the rocks were exposed to the water and the rigorous shaking?
Day before the lesson:
1) Each group of rocks will be equally separated into three piles. Rocks will be placed onto a sheet of paper labeled “A”, “B”, and “C”.
2) Each container and jar will be labeled “A”, “B”, and “C”.
3) Stones from pile “A” will be placed into container “A ” and filled half way with water. The same will be done to piles “B” and “C”.
4) Students will record their observations in their science journals.
5) The stones will be left to sit in the water overnight.
Anticipatory Set: The lesson will begin with students being told the objective. They will be asked to recall the preparation we performed for today’s lesson. Students will be asked to think about what covers the Earth’s surface and the different ways that the surface can change. Answers will be given and written on the board.
Direct Instruction/Guided Practice: Students will be shown an interactive demonstration of how weathering and erosion occur (http://www.learner.org/interactives/rockcycle/change3.html). Vocabulary paired with pictures will be introduced. Students will be asked why it would be difficult for us to observe weathering and erosion if we went outdoors. They will be told that we can get an idea of how weathering occurs on the Earth’s surface by conducting an experiment using rocks and water. Students will be told to observe the containers after they have sat in water overnight and record their observations in their science journals. Students will be asked if they notice any difference in the containers from the previous day. Observations will be discussed.
Independent Practice: Students will be told that they are going to act like the environmental elements we discussed to show the effects of weathering on our rocks. The class will be divided to accommodate the four stations (five per station). Each station will be equipped with written, step-by-step instructions and pictures to accommodate ELL’s and visual learners. Students will be told to take turns shaking the containers. They will start with container “A” and shake it hard 1, 000 times (math connection-students will be asked how many times each student will have to shake to equal 1, 000). After the shaking has taken place, the students will work together to remove the water into jar “A” and to pour the rocks onto the tray. Students should observe the rocks and the water and document their findings.
Students will be told to use the same process for container “B ” but to only give 300 shakes. Then, remove the rocks and pour the water into jar “B”. They should then observe the rocks and the water and document their findings. Students will be instructed not to shake container “C”, but to remove the rocks and pour the water into jar “C”. They should observe the rocks and the water and document their findings. Students should then compare all of the rocks and the water from which they came.
Closure: Students will gather as a whole group with their science journals to discuss their findings. Students will be told that they have just witnessed the process of weathering. Students will be asked to recall the scientific method (and referred to the diagram in the classroom). The focusing questions will lead the class in group discussion of the experiment. The students will be asked:
- Which pile of rocks acted as our control group and why?
- How did the three piles of rocks differ and why?
- How did our experiment show what happens to rocks and stones through the water erosion process?
Lastly, students will then be taken outside to look for signs of weathering on native rocks and erosion of the school grounds. This hands-on activity will act as an assessment.
Students will be assessed according their participation in the experiment and the group discussions. Students will be assessed according to their ability to identify and explain at least one way weathering and erosion changes the Earth’s surface.
Alternative assessments may be given to students who would be better served explaining through a drawing, by modeling using rocks or through a short written retelling.
1) An acid such as vinegar or lemon juice could be used to show chemical erosion.
2) Students could fill a plastic Easter egg with water, close it, then freeze it. Students can see the ice crack the egg. This shows the freeze and thaw cycle.