How do we know how much oxygen is in the atmosphere?

Introduction/Background:

How much oxygen is in our atmosphere?

How do we know oxygen is in our atmosphere?

-Life (explain) -Combustion (explain)

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What are your controlled variables?

How were they controlled?

Why were they controlled?

Be sure to pick up a Lab Report Rubric to know what you are supposed to include in your lab report!

Hypothesis

Statement/Prediction :

If I use…..then I think…..because...

Complete: Materials, Procedure, Data Table, Class Data, Conclusion

Experiment

Materials List:

• candle
• beaker (200ml water)
• test tube
• marker
• tray
• penny
• lighter
• graduated cylinder

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Procedure: (should be step-by-step, numbered instructions in your own wordswithout using (I, we, you etc). See provided paper

Example

1. Find the volume of the test tube by pouring water to the top and measure the volume using the graduated cylinder.

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Data

Create a table with your data that you collected from your experiment. Example below:

Analysis : show calculations, and answer questions below

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% Oxygen in air =

Initial Volume

Oxygen used

X 100

1. Why did the water go into the test tube?
2. What is your % of Oxygen? How does your data compare to the rest of the class?
3. How does your % of oxygen compare to the actual % of oxygen in the air?
4. As altitude/elevation increases, the density of the air decreases. Give 2 locations in the U.S. that have these different densities based on altitude/elevation
5. Why do people have a difficult time breathing or excersizing in Denver? Provide an example.

Conclusion : in complete paragraph

The purpose of this experiment was . . .

(What did you do, how did you do this, and what did you use?)

My hypothesis was….(restate your hypothesis)

(Was your hypothesis correct or incorrect?)

The data shows . . . .

(use specific numbers from your collected data to show trends and outcome)

Things that could have caused error were . . .

(measurement, procedure, calculations, process mistake)

The quality of this data could be improved by . . .

(How might you do the experiment differently for better results?)

The results of this lab can explain why/how. . .

(Real World connections or examples that connect to topics in unit.)