In this lesson, students discover the chemistry behind the ozone layer’s depletion and recovery and then apply their learning to advocate for climate action.
Step 1 - Inquire: Students investigate the properties of ozone and oxygen to understand how the ozone layer protects life on Earth.
Step 2 - Investigate: Students learn about the Chapman cycle and complete a jigsaw activity about the causes of ozone depletion.
Step 3 - Inspire: Students create a social media post about a climate issue that is important to them, inspired by the success of the Montreal Protocol.
This lesson can be integrated into a unit on thermochemistry.
The lesson can be used in an IB Chemistry class.
This addresses applications and skills in Topic 5.3 (SL & HL) of the old syllabus (last assessed 2024).
This addresses linking questions in Structure 2.2.11 and Reactivity 3.3.2 of the new syllabus (first assessed 2025).
This lesson can be used in an AP Environmental Science course to address Topics 9.1 and 9.2.
Students apply their knowledge of bonding, atomic structure, and thermochemistry to examine a real-world problem.
Students learn about an environmental success story.
Students need access to computers to complete the Jigsaw Activity in the Investigate section and to do research and create their social media post in the Inspire section.
Students should be familiar with algebra skills. They should be able to plug into an equation and then solve for the missing variable.
Students should have prior knowledge of bonding:
Lewis dot structures
Bond length and strength in covalent compounds
Students should have prior knowledge of the electromagnetic spectrum (EMS):
Shorter wavelengths of light have more energy than longer wavelengths.
Shorter wavelengths of light have higher frequencies than longer wavelengths.
Ultraviolet (UV) light has wavelengths between 10 and 400 nm. Its energy is too high to be seen with the naked eye.
Students should have some prior knowledge of thermochemistry:
Bond making is exothermic.
Bond breaking is endothermic.
Bond enthalpies are defined as the kJ of energy required to break one mole of gaseous covalent bonds, averaged over similar molecules.
For an extension on how the temperatures in different parts of the atmosphere affect the ozone layer, students can read this article and engage in further research.
Groupings for the Jigsaw Activity can be mixed-level in order to ensure students have support with understanding their assigned reading, or different jigsaw options can be assigned to different groups based on ability.
Group A reads a background article written for students, which most high school students should be able to read and understand
Group B listens to a podcast. This option is ideal for students who struggle with reading in English.
Group C reads a scientific journal article, which requires a higher reading level to read and understand.
The social media post could be created alone or in groups and tailored for students to share in different ways. For example, students could share their posts internally (Google Classroom, Schoology, etc.) if there are restrictions on social media use at school.
This thorough lesson gives students the opportunity to study the ozone layer's composition, chemical processes, physical characteristics, and significance for shielding people from dangerous UV rays. Additionally, students will study how ozone is destroyed, how the Montreal Protocol was used to manage the hole in the ozone layer, and how to use the model to address the present global climate crisis. After extensive fact-checking, the lesson passed our scientific credibility process and is recommended for teaching.