Atmospheric Processes - Convection

In this two-part lesson plan/activity, students will observe convective currents in water and observe the air as a fluid. This activity demonstrates how convection currents work both in a liquid and a gas. It can be done in teams or as a demo.

Weblink address (URL): 
Atmospheric Processes - Convection

Standards & Objectives

Learning objectives: 

Learning Goals:

Part 1

  • Students will understand that temperature changes can cause density changes in water. 
  • Students will be able to express that the same phenomenon happens in air. 
  • Students will understand that temperature-driven density changes will produce currents in a fluid medium.

Part 2

  • Students will understand that air is a fluid and behaves in ways we expect of other fluids.

Lesson Variations

Blooms taxonomy level: 
Understanding
Differentiation suggestions: 

Modifications for Alternative Learners:

  • Limited language students should be able to rely on drawings and diagrams for explanations.

Variations:

  • Repeat the experiment with the following variations. Ask students to record their observations after each variation. Make certain they start each trial with a clean saucer of water. Having several dump buckets placed around the classroom will be helpful.
  • For the following three trials, place a cup of hot water under the center of the saucer as shown. Fill the cup almost to the top.

Helpful Hints

Materials:

Part 1: Currents in Water

For the class:

  • Pitchers or jugs for water
  • A source of very hot water, such as an electric teakettle, hot plate and regular kettle, or coffee maker (hot tap water is usually not hot enough)

For each team of students:

  • Clear plastic plant saucer 8 to 10 inches wide. Caution: DO NOT use saucers with concentric raised rings on the inside bottom; radial ridges are okay
  • Pitchers or jugs for hot and cold water
  • Food coloring
  • Small container for food coloring (a small cup would work fine)
  • Medicine dropper or pipette
  • Four Styrofoam cups
  • Data sheet

Part 2: Air is a Fluid:

  • Baking soda
  • Vinegar
  • 500 ml beaker or glass jar of similar size
  • Candle (a small votive candle is ideal)
  • Matches
  • Strip of poster board or cardboard about 12" by 3" (old file folders work well)

 

References

Contributors: 
Virginia Cooter
Originator: 
Ayers Institute for Learning & Innovation