Climate Change Toolkit: How Many Molecules Make a Trace Gas?

• The purpose of this worksheet is to help students understand that even though carbon dioxide is a "trace gas" in the atmosphere, there are still many molecules of it present, even in a small space like a water bottle.
• This worksheet addresses the question, "How many molecules of carbon dioxide are in a one-liter bottle of air at standard pressure and temperature?"
  

Positives

• The single calculation in this activity helps students visualize and conceptualize the amount of carbon dioxide molecules present in a given space.
• Students use real data from the Mauna Loa Observatory to discover carbon dioxide concentrations in the atmosphere and they apply that information to answer the questions.

Additional Prerequisites

• Students should be familiar with the Ideal Gas Law.
• Students should be able to solve equations and complete conversions with multiple fractions.
• Students should be able to plug variables into equations and calculate unknowns using multiplication, division, addition, and subtraction.

Differentiation

• Consider having students work in pairs if they are intimidated by solving the equation.
• Bring in a bottle for display. Have students make predictions about the amount of carbon dioxide in the bottle before completing the worksheet.
• This experiment from the same organization can be used in combination with this calculation worksheet to help students understand the warming effects of carbon dioxide.
• Additional resources to pair with the lesson are A More Accurate Way to Calculate Emissions and What are Carbon Emissions? (Green Transportation #1).

This resource addresses the listed standards. To fully meet standards, search for more related resources.