How can we make sand stand tall?
What is density? Mass? Volume? How are they related?
Why should we make sand dense? How can we make sand denser?
What is sand compaction and sand densification?
Explain the terms “sand compaction” and “sand densification” in their own terms.
Explain that density of sand is defined as mass of the sand per volume of the sand.
Explain that patting the sand in a container will make the sand denser.
Calculate the sand density.
Mass, volume, density, sand compaction, sand densification
Measure volume, mass; determine the density of sand
Change in density of sand
Differences in volume and density of sand
The facilitator first asks “What is mass? What is volume?”. After some students answer the questions, the facilitator reviews the concept of “volume” and “mass” with students. The facilitator could use cotton balls, little rocks, wood/rubber balls to demonstrate some matter with similar volume but different mass and ask students why their mass are different. Some students may come up with the concept of density.
The facilitator could review the tools that we use to measure the “mass” and the “volume” of matter. Review related measurement units in metric systems for both mass and volume. For example: common units for mass (kg, g, mg, etc.); and common units for volume, this would depends on what volume we will be discussing: solids (cubic meters) or liquids (liters). [This part of the knowledge will prepare students to work on the worksheet later]
Then the facilitator plays the video to introduce the idea of density, and prompt student thinking with following discussions: What is mass? What is volume? What is the relationship between the two? What is density? How density is measured?
The facilitator will ask students following questions to guide student thinking while watching the video and after watching the video. While watch the video, keep (“this vocabulary in mind” instead of “in mind of these”) vocabulary:
What is mass? What is volume? What is density?
What did you learn from this video?
What is matter? Can you identify matter in this classroom?
Relative Density of Soil in a Jar
Small-group Hands-on Scientific Inquiry 30 minutes
Grounded (chp. 18)
The facilitator starts with some prompt questions such as, “What is the mass of this jar” and “What is the volume of the jar?” “Are they the same?” by showing students a jar. The facilitator shows a big pile of sand and asks, “How do we measure the mass and volume of the sand?”and “Is it easy to find the mass and volume of the sand?” “why or why not?” (“The facilitator then” instead of “Then facilitator”) asks students to guess the mass of the big pile of sand. The facilitator will introduce the measurements units that students will be using for this experiments. For example, units for mass as kilogram or gram. Facilitator will demonstrate how to use scale to measure the mass of a jar and sand. Facilitator then asks students to determine the volume of the jar, and then asks “How much sand can we pack it into this jar?” Facilitator prompts learners to determine the volume of the sand in the jar. Students would guess. Then facilitator can break students into small groups to work on the hands-on activity.
Weigh the empty jar and document its mass on the worksheet
1. Fill the jar with sand.
2. Weigh the filled-jar, document the weight of the filled-jar with the sand.
3. Document the volume of the sand by reading the label on the jar.
4. Place a 2 kg load on the sand. Observe the sand level. Document the sand level.
5. Calculate the density (ratio) of the sand in the jar.
6. Pat the sand to densify the sand in the jar
7. Weigh the sand in the jar and document it.
8. Read the new level of the sand to find volume.
9. Place a 2 kg load on the sand. Observe the sand level. Document the sand level.
10. Calculate the density (ratio) of the sand in the jar.
11. Fill the rest of the jar with sand. Pat it again. And fill more if needed until the sand is patted in the whole jar.
12. Weigh the jar and sand again and document the weight.
13. Read the new level of sand to find volume.
14. Place a 2 kg load on the sand. Observe the sand level. Document the sand level.
15. Calculate the density (ratio) of the sand in the jar.
10 minute break
Whole Group Discussion
Facilitator asks students share their observations and compare across groups. Students can make a whole-group poster displaying their different ideas. The facilitator can ask more questions as students write their ideas to promote further thinking.
“Was it easy to find the sand mass and volume?”
“Why did you pat the sand?” Facilitator introduces the term “sand compaction” and “sand densification.”
“Between the jars with high and low density which one do they think would be stronger?”
“What is a benefit of condensing the space between the sand?”
“Can you think of a time you have condensed sand? Why did you do this?” The facilitator can probe students to consider sand castles.
The facilitator says, “This is a working document that can be added to as we learn more!”
End of Session Reflection and Debriefing
5-10 minutes (will be recorded)
What did I learn today?
What worked well?
What didn’t work well?
What can I/we do differently next time?
Do you have anything else to share?