Sink or Float: All Liquids Do Not Have the Same Density

Cathy Haase
Shirley Hills Primary
Mound, MN
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Summary

The students will determine through experimentation, if like amounts, but different densities of sugar water will sink or float in a container of water. Students will complete a checklist to record their predictions and actual results.


Learning Goals

  1. Students will learn that similar amounts of liquids will not act the same in a container of water.
  2. Students will use critical thinking skills to determine their predictions.
  3. Students will learn to transfer their predictions and subsequent actual results onto a simple checklist form.
Vocabulary:
-Prediction
-Float
-Sink
-Buoyancy
-Equal amounts
-Volume
-Analyze
-Measurement terms

Context for Use

Time needed: 30 - 40 minutes.
Prior knowledge: Children should be familiar with using a checklist.
Curriculum: Standard for water.
Adaptations: The experiment can be done in individual or small group, or as a teacher demonstration. Older students can use graphing and do this with more written analysis

Description and Teaching Materials

Materials:
-4 identical containers
-Bottle type with cap
-Holding approx. 4oz., lg container (clear plastic)
-Cork
-Marble
-Penny
-Craft stick
-Sugar
-Food coloring
-Newspaper
-Prepared check list for each child and one overhead for teacher
-Clipboards, if kids not at desks
-Pencils

Preparation:
Put equal amounts of water in 4 large containers. In 1st container, put no sugar in water, in 2nd put 2 spoonfuls of sugar, in 3rd, put 4 spoonfuls of sugar, etc.

Introduction:
With large clear container filled with enough water to cover an upright 4oz bottle, review floating and sinking by using cork, marble, penny, craftstick (or similar materials). First have kids predict "float or sink" and individually put each item in the water.
Discuss and mark checklist.Ask them to predict if remaining bottles will sink or float.
Mark charts.
Continue to put each bottle in the container and record and discuss results.

Teaching Notes and Tips

As with any experiment, try your choices of fluids before you do this in front of the students. Be sure to demonstrate how to gently put containers in water-no slam dunking!

Assessment

Through the checklists and discussion, you should notice children seeing the pattern of results.

Standards

II. PHYSICAL SCIENCE
A. Structure of Matter
Standard:
The student will understand that objects have physical properties

References and Resources