Solid and Liquid Density Investigation

Rhonda Powell
Park Elementary
Le Sueur, MN
Author Profile

Summary

In this lesson, students will have the opportunity to predict and observe the outcome of the density of a variety of solids to water. They will then predict and observe the outcome in comparing the density of water with other liquids. By the end of the lesson, students will be able to create an understanding of what density means.


Learning Goals

  1. Students will review the terms: liquid, solid
  2. Students will predict and then compare the density of different solids to water.
  3. Students will predict and then compare the density of different liquids to water.
  4. Students will create an understanding of the term "density" after observing different experiments.

Context for Use

This activity is for second grade but can be adopted for 1st or 3rd in a public elementary classroom for about 20 students. There will be whole group learning and small group learning taking place. The lesson can be taught in a one hour-long lesson or two half-hour lessons. Students will have previously learned about matter, knowing the difference of solids, liquids and gases. This activity will fit into our science unit of matter. The experiments will allow the students to inquire through observing, predicting and then exploring. The experiment with density of solids could be set up as a center and the students would complete the worksheet to turn in.

Description and Teaching Materials


Materials needed:
4 of the following items: golf ball, bouncy ball, paper clip, block, rock, golf tee, plastic cap, and clothespin.
4 clear containers to hold water and to put one of the above items in at a time
4 small towels, or clothes
1 crayon
Water for containers
3 clear containers (about 1 pint size to 1 quart size)
Food coloring
Oil (1 c.)
Pepsi (1/2 c.)
Karo syrup (1/2 c)
Worksheets that are attached

Have the terms solid, liquid and gas on the smart board. Review what these three words can be categorized as. (Matter)
Explain that we will be talking about solids and liquids today and doing some comparisons with them. Have students look around the room and name 1 solid and 1 liquid to a neighbor. If they cannot think of anything in the classroom, think of something in their kitchen.
Write the word density on the smart board. Tell the students that we will be experimenting with solids and water and discover which items are more dense or less dense than water. They need to be thinking about the word density and be able to explain what they think it means by the end of today's lesson. Demonstrate what they will be doing in small groups.
Put water in a container. Hold up the crayon and have students predict what they think will happen when the crayon is placed in the water. Model on the smart board how students will record the prediction on their worksheet. Perform the experiment with the crayon and discuss the outcome. Then record which has greater density, the crayon or water, on the smart board. Put the students into groups. They need to select one student to get the supplies that are in a bag on the table. Each student will need a pencil, clipboard and worksheet. Explain that they may pass the solid object around in the group to feel. Also explain that they will need to take turns with who puts the object into the water.

As students are engaged in the activity, I will walk around and listen to discussions, ask questions to get the students thinking about what density means and observe the interaction among the groups. As groups finish, they will need to clean up their area and return the supplies to the table. They will need to keep their worksheets out on their desk for discussion.
When all are done, share their results and record on the smart board worksheet to refer back to later.

Now explain that we just experimented with density with solids and water, next show what water, Pepsi, oil and corn syrup look like in a clear container. Discuss the comparisons that are observed. Share that we are going to compare the density of different liquids. Put drops of food coloring in the water so they can notice the difference better when combined with other clear liquids.

Have the students gather around a table so that all can see. They will need a worksheet for comparing density of liquids, clip board, colored crayons or colored pencils, pencil. Students need to record their prediction of what will happen with number 1. Pour 1/2 cup of colored water into a clear container and then add 1/2 c. oil. Have students share their observation and then record. Continue with the same procedure for numbers 2 and 3. (Note: The Karo Syrup will have greater density than the water to start with. Tell the students that you will keep that one out on display and we will continue to observe any changes. When there are changes, discuss why it changes in time?)

Have the students look back at their results of solids and which objects had a greater density than water. Hopefully they will come to a conclusion that objects that are compacted together tightly are more dense than water and will sink to the bottom. The lighter objects or, less compacted together objects, stayed afloat. Then have them compare the results of liquids and which have a greater density. Do the liquids fill the shape that they are in? How can some separate and one liquid go to the bottom and one stay on top? Record their discovery of what density means to them. assignment handout (Microsoft Word 23kB Aug21 08)

Teaching Notes and Tips

This activity will allow small group discovery where each student will be involved. It will also allow for full group so that you can keep the discussion going with asking higher order thinking questions. Having the groups planned out in advance is usually more beneficial

Assessment

I will be doing observations of their involvement. I do not take grades in science at this grade level. The worksheets could be used for scoring if a grade is needed.

Standards

Grade 2:
I.B. 1.
Use appropriate tools to gather data
II. A. 2.
classify solids, liquids, and gases
II. A. 3.
Know that solids have a definite shape and that liquid take shape of their container

References and Resources