Decomposition Over Time

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Students will be able to observe and analyze decomposing items over time and draw conclusions based on data.

Big Idea

Students will observe their organic and inorganic materials for a final time and draw conclusions about decomposition.


1 minutes

Warm Up

10 minutes

To begin the lesson, the students and I will meet on the carpet for a whole group discussion. We will review our experiment on decomposition. I will allow students to share their notes from the first day of the experiment when we first placed the items from their lunches inside of the clear jars. Allowing the students to share their data from the first day of the experiments reactivates their thinking regarding the observations the recorded on day one. It also gives the students a refresher on the information to make it easier to compare with the data that they will be collecting today.


20 minutes

Once students have shared their illustrations and notes from the first day of the experiment, I will pass around each clear container of organic items that have been decomposing in our classroom window sill. I will encourage the students to take very descriptive notes and illustrate exactly what they see for a final time. As students pass down the jars, I will observe them writing and ask probing questions to encourage inferencing and critical thinking. Some questions I may ask are, " Why do you think these changes have occurred? What may have caused these changes?"

Next, I will distribute the inorganic items that we placed inside of the jars for our experiment. I will encourage the students to continue using specific details and illustrations to document their findings.

Once students have completed their observations and recordings on the indoor organic and inorganic items, we will transition to the courtyard. Here the students will observe the same organic and inorganic items that were inside, however were kept outside. I will continue to observe the students as they record their observations. I will also continue to ask questions that encourage critical thinking and inferencing. It is extremely important for students to complete their recording sheets because they will need the information to compare the data over time. The students will need to draw a conclusion based on the changes that they have observed. It is crucial that the students understand that organic items decompose at a much faster rate and inorganic items. They also must make note that location also effects the decomposing of items.

Once the students have completed their recording sheets, I will ask them to compare the indoor and outdoor items to draw a conclusion between the two items.

Wrap Up

10 minutes

Once students have completed their observations, we will transition back to the classroom and have a seat on the carpet with our recording sheets. I will ask students to share their recordings of their organic items and compare it to the observations that were recorded back on day one of the experiment. I will ask students to predict why specific changes might have occurred; for example, why the whole grain bread molded extremely faster indoors rather than outdoors.

Next, we will focus on the inorganic items. Most students are going to note that there has not been a change in these items. We will discuss why no changes are evident. I will explain to students that the inorganic items may indeed decompose, but it will at a much slower rate than the organic items because the organic items are produced directly from living things. 

Lastly, to conclude the lesson, students will be given the opportunity to draw conclusions based on their observations and share it with the class.