Density Curriculum

Section 4—Lesson 14: Layering Liquids: How Does Density Affect Sinking or Floating?

Understanding Goals

Subject Matter

• Density is one variable involved in sinking and floating.
• When considering whether a liquid will sink below or float on another liquid, you have to compare the densities of the liquids.
• The liquid with the greater density will sink and the liquid with the lesser density will float. In cases where there are more than two liquids, the liquids will layer from least dense to most dense, top to bottom.
• Gases also layer from least dense to most dense, top to bottom, as is the case with the gases in our atmosphere.

Causality

• The role of density in sinking and floating is described by Relational Causality. Students' default pattern is to use simple linear causal models.
• Layering liquids helps to make the role that the liquid plays in sinking and floating obvious.