Analogy of Relative Humidity By Pamela Blackford Martinsburg High School 1.Place students in small groups. Each group will need beakers, supply of sugar, and 2 spoons. (Have students boil water themselves or have a common container of boiling water.) 2.Record observations in a journal. a. 1 st beaker: Measure boiling water and record temperature. Add one teaspoon of sugar at a time to water and stir. Does it all dissolve? Continue to add sugar one teaspoon at a time until sugar no longer dissolves. Record your observations. b. 2 nd beaker: Using room temperature water, stir in one teaspoon of sugar at a time until all the sugar no longer dissolves. How many teaspoons of sugar did it hold? c. 3 rd Beaker: Repeat steps above using ice cold water. How much sugar did it hold? Measure and record temperature. 3.Students will use their data to make a graph showing the relationship between the amount of sugar dissolved and the temperature of the water. 4.After the graph is completed, provide students with a water temperature. Ask them to use their graph to estimate the amount of sugar that can be dissolved in it. 5.Verify the estimate through experimentation. 6.Plot the results on the graph. Ask student to suggest possibilities for any differences found between estimate and experimental result. 7.Repeat steps 4, 5, and 6 with another water temperature. 8.Ask students to explain the relationship on their graph. 9.Have students look up the definition of relative humidity. 10.Ask students to relate their results to develop a simple definition of relative humidity. 1.Place students in small groups. Each group will need beakers, supply of sugar, and 2 spoons. (Have students boil water themselves or have a common container of boiling water.) 2.Record observations in a journal. a. 1 st beaker: Measure boiling water and record temperature. Add one teaspoon of sugar at a time to water and stir. Does it all dissolve? Continue to add sugar one teaspoon at a time until sugar no longer dissolves. Record your observations. b. 2 nd beaker: Using room temperature water, stir in one teaspoon of sugar at a time until all the sugar no longer dissolves. How many teaspoons of sugar did it hold? c. 3 rd Beaker: Repeat steps above using ice cold water. How much sugar did it hold? Measure and record temperature. 3.Students will use their data to make a graph showing the relationship between the amount of sugar dissolved and the temperature of the water. 4.After the graph is completed, provide students with a water temperature. Ask them to use their graph to estimate the amount of sugar that can be dissolved in it. 5.Verify the estimate through experimentation. 6.Plot the results on the graph. Ask student to suggest possibilities for any differences found between estimate and experimental result. 7.Repeat steps 4, 5, and 6 with another water temperature. 8.Ask students to explain the relationship on their graph. 9.Have students look up the definition of relative humidity. 10.Ask students to relate their results to develop a simple definition of relative humidity minutes None listed Develop a graph with experimental data that will help students construct their own definition of the relationship between air temperature and the amount of water the atmosphere can hold. 30 beakers Sugar Measuring spoons (10-15) Hotplates Graph paper 30 beakers Sugar Measuring spoons (10-15) Hotplates Graph paper Journals are reviewed according to the following scale: A.Journal very complete, neat, well written. Student’s ideas are supported by observations. B.Journal complete, neat, needs some grammatical work. Most ideas are supported by observations. C.Journal lacking some information, not very orderly, needs major grammatical work. Very few ideas supported by observations. D.Journal incomplete. Observations lacking. Very few ideas presented. None supported by observations. Journals are reviewed according to the following scale: A.Journal very complete, neat, well written. Student’s ideas are supported by observations. B.Journal complete, neat, needs some grammatical work. Most ideas are supported by observations. C.Journal lacking some information, not very orderly, needs major grammatical work. Very few ideas supported by observations. D.Journal incomplete. Observations lacking. Very few ideas presented. None supported by observations. None listed Objective Materials and Equipment Materials and Equipment Time Procedures Assessment Further Challenges Further Challenges Overview Teaching Suggestions Safety Note