Crayon Density
GOAL: Students explore the relationship between density,
volume, and mass.
BEHAVIORAL OBJECTIVE: Students will design and conduct an
experiment to determine why some crayons float and some crayons do not
float. Students will discuss the meaning of density, mass, and volume and list
examples of each. Students state that objects that float in water have a density of
less than 1 gm/cm3, and objects that sink in water have a density greater than 1
gm/cm3. Students find the density by dividing mass by volume. Students work in
cooperative groups of four.
INSTRUCTIONAL OBJECTIVE: The teacher will arrange students in groups of
four and provide each team with the materials listed below. The teacher will
engage the students in a discussion about density, volume, and mass posing
questions for students to discuss and record in their groups. The teacher will
explain the experiment and act as a facilitator as students explore the concept of
density using crayons. The teacher will engage the class in a discussion about their
results and have students record what they learned about density, mass, and
volume in their journals.
1. Discuss the meaning of density. Provide examples.
2. Find and record the mass of crayons.
3. Find and record the volume of the crayons.
4. Calculate and record the density of the crayons.
5. Construct a graph using the data collected.
6. Predict which crayons will float and which crayons will sink.
7. Design and conduct an experiment to test the crayons. Record the results.
8. Share the results with the class.
MODES OF INSTRUCTION: Students:
1.) participate in class/group discussion.
2.) formulate and test the hypothesis, experiment, gather data, draw conclusions,
and communicate the results.
3.) review the learning through group discussion and journal keeping.
MATERIALS:
8 boxes of eight crayons
8 balance scales
8 small tub of water
8 50 mL graduated cylinders
METHODS OF EVALUATION:
1. Check the completeness and accuracy of
data collected and graphs constructed.
2. Answer the following questions in the journals:
*What causes some crayons to float and other
crayons to sink.
*Explain how you arrived at your hypothesis.
*Teacher observation of group/class participation.
ACTIVITIES FOR REMEDIATION:
Operation Chemistry: Density and Buoyancy Activities 1-5. The following
activities review density, mass, and volume in more detail to aid in understanding.
Activity 1. Students use bouillon cubes and butter to explore density and compare
the density of these two items.
Activity 2. Students weigh one small baggie of sand and one small baggie of foam
peanuts that have the same mass to explore density.
Activity 3. Students predict the density of six different objects in baggies. All
baggies have the same mass.
Activity 4. Students predict the volume of six different objects in baggies. A
baggies have the same volume.
Activity 5. Students consider the relationship between mass, volume, and density
by examining a variety of samples of substances having the same and different
volume, the same and different mass, and the same and different density.