prepare a scientific report to show that air has oxygen with necessary diagrams?

Title: Investigation of the Presence of Oxygen in Air

Introduction:
Oxygen is a vital component of the Earth's atmosphere, making up approximately 21% of the air we breathe. It is essential for the survival of most living organisms, as it is used in cellular respiration to produce energy. In this experiment, we aim to demonstrate the presence of oxygen in air through a series of chemical reactions.

Materials and Methods:
1. Test tube
2. Manganese dioxide (MnO2)
3. Hydrogen peroxide (H2O2)
4. Candle
5. Matches
6. Lime water (Ca(OH)2)

Procedure:
1. Place a small amount of manganese dioxide (MnO2) in a test tube.
2. Add hydrogen peroxide (H2O2) to the test tube and observe any changes.
3. Light a candle and place it in a separate test tube.
4. Hold a test tube of lime water (Ca(OH)2) over the flame of the candle and observe any changes.

Results:
- When hydrogen peroxide is added to manganese dioxide, oxygen gas is produced, as evidenced by the formation of bubbles.
- When the candle is lit, it consumes oxygen from the air, leading to a decrease in the volume of air in the test tube.
- When the test tube of lime water is held over the flame of the candle, the lime water turns milky, indicating the presence of carbon dioxide, a byproduct of combustion.

Discussion:
The results of this experiment demonstrate the presence of oxygen in air. The production of oxygen gas when hydrogen peroxide is added to manganese dioxide confirms the presence of oxygen in the air. Additionally, the decrease in volume of air in the test tube when the candle is lit further supports the presence of oxygen, as the candle consumes oxygen during combustion. The formation of carbon dioxide when the lime water is exposed to the flame of the candle also indicates the presence of oxygen, as oxygen is required for combustion to occur.

Conclusion:
In conclusion, this experiment provides evidence of the presence of oxygen in air. The production of oxygen gas in the reaction between hydrogen peroxide and manganese dioxide, as well as the consumption of oxygen during combustion, demonstrate the importance of oxygen in the Earth's atmosphere. Further studies could explore the concentration of oxygen in air and its effects on living organisms.

Scientific Report on the Presence of Oxygen in Air

Introduction

Oxygen is an essential component of air, necessary for the survival of most living organisms. This report aims to scientifically demonstrate the presence of oxygen in air through various experiments and observations.

Methods

Experiment 1: Glowing Splint Test

- Materials:
- Wooden splint
- Fire source (e.g., lighter)
- Procedure:
1. Light the wooden splint and allow it to burn until the flame stabilizes.
2. Extinguish the flame by blowing it out.
3. Immediately insert the glowing splint into a glass jar filled with air.

Experiment 2: Rusting of Iron

- Materials:
- Iron nail
- Glass beaker
- Water
- Procedure:
1. Fill the beaker with water.
2. Drop the iron nail into the water.
3. Observe the nail over a period of several days.

Experiment 3: Combustion of a Candle

- Materials:
- Candle
- Glass jar
- Procedure:
1. Place the candle in the center of the glass jar.
2. Light the candle.
3. Observe what happens to the candle flame.

Results

Experiment 1:
- The glowing splint reignites and burns brightly when inserted into the glass jar.

Experiment 2:
- Over time, the iron nail becomes covered in a layer of rust.

Experiment 3:
- The candle flame continues to burn and emits light and heat.

Discussion

Experiment 1:
- When the wooden splint is burned, it produces carbon dioxide, which is heavier than air and displaces the oxygen in the glass jar. When the glowing splint is inserted into the jar, the remaining oxygen comes into contact with the carbon and reignites the fire.

Experiment 2:
- Rust is formed when iron reacts with oxygen in the presence of water. The formation of rust indicates the presence of oxygen in air.

Experiment 3:
- The combustion of the candle requires oxygen. The continued burning of the candle flame indicates that there is sufficient oxygen in the glass jar.

Conclusion

The results of these experiments provide strong evidence for the presence of oxygen in air. The glowing splint test, the rusting of iron, and the combustion of a candle all demonstrate that air contains oxygen, which is essential for the survival of living organisms.

Additional Diagrams

[Image of glowing splint test setup]

[Image of rusted iron nail]

[Image of candle burning in a glass jar]

class 7