Objective
By the end of this lesson, you will be able to understand the properties and importance of oxygen in chemistry.
Materials and Prep
- Oxygen gas (can be obtained from a supplier or generated using electrolysis)
- A glass jar or container
- A candle
- A lighter or matches
- Safety goggles
Prior knowledge needed: Basic understanding of atoms, elements, and chemical reactions.
Activities
- Introduction to Oxygen: Begin by discussing the importance of oxygen in our daily lives. Talk about its presence in the air we breathe and its role in supporting combustion.
- Oxygen and Combustion: Set up a demonstration by placing a lit candle inside the glass jar. Carefully cover the jar with an airtight lid, ensuring no oxygen can enter. Observe how the flame gradually extinguishes due to the lack of oxygen.
- Reintroducing Oxygen: Remove the lid from the jar and allow oxygen to enter. Observe how the flame reignites as oxygen is reintroduced into the environment.
- Properties of Oxygen: Discuss the physical and chemical properties of oxygen, such as its colorless and odorless nature, its role in supporting life, and its reactivity with other substances.
- Experiment with Oxygen: Encourage the student to conduct their own experiments using oxygen, such as testing its effects on rusting or observing its reaction with different elements or compounds.
Ninth Grade Talking Points
- "Oxygen is a chemical element with the symbol O and atomic number 8."
- "It is the third most abundant element in the universe and makes up about 21% of the Earth's atmosphere."
- "Oxygen is essential for respiration, allowing living organisms to convert food into energy."
- "It supports combustion, which is the process of a substance reacting with oxygen to produce heat and light."
- "Oxygen is highly reactive and can form compounds with almost all other elements."
- "It is involved in various chemical reactions and plays a crucial role in the formation of ozone in the Earth's stratosphere, protecting us from harmful ultraviolet radiation."