Cooling Gases Lesson Plan for 7th Grade Students

Topic: Cooling gases

Objectives & Outcomes

• Students will be able to explain how gases cool and the processes involved.

Materials

• Jar or container with gas
• Ice cubes or ice cold water
• Thermometer
• Timer or clock
• Pen and paper for each student

Warm-Up

• Start by asking students what they know about gases and how they can change. Write their answers on the board.
• Next, ask students if they have ever seen gas change from a liquid to a solid (e.g. steam turning into water or ice) or from a solid to a liquid (e.g. water turning into ice or ice turning into water). Have them share their experiences.

Direct Instruction

• Next, introduce the concept of cooling gases by explaining that as a gas cools, its molecules slow down and become closer together, which causes them to become denser and eventually turn into a liquid or solid.
• Show students an example of how gas can be cooled, such as by using ice cubes or a frozen bottle to cool down a can of soda. Have students observe the process and record their observations on their notes sheets.

Guided Practice

• Next, have students work in pairs to conduct their own experiment on cooling gases by using a can or bottle of soda and some ice cubes or frozen water bottles. Have students first calculate how many ice cubes or frozen bottles are needed to cool down a particular amount of soda. Then, have them conduct the experiment and record their observations on their notes sheets.
• As a class, discuss the different ways that the gas was cooled in each experiment and how this affected the density of the gas. How did the gas change from a gas to a liquid or solid?

Independent Practice

• For independent practice, have students work in groups to design and conduct their own experiment on cooling gases. They can use materials such as soda, ice cubes, and frozen water bottles, but they can also include additional variables such as different types of soda, different sizes and quantities of ice cubes and frozen water bottles, and different temperatures in the room. Have students record their observations and draw conclusions from their experiments.

Closure

• Review the objectives of the lesson and have students share their findings from their independent experiments. Remind them that cooling gases experience a change in volume as they get cooler and that this is particularly pronounced in gases that are denser than air, such as carbon dioxide and helium.

Assessment

• Observe students during the guided and independent practice activities to ensure that they are accurately measuring the temperature and volume of their gases and accurately recording their findings. Review their completed worksheets to assess their understanding of the concepts covered in the lesson.