National Day Calendar Classroom - November 2019 - STEM

National Day Calendar Classroom - November 2019 - STEM


The classroom dives into STEM week with a project that studies the preservative qualities of common household products.

Since apples are in season, they will be our test object. We can also enjoy a healthy snack while we’re at it. So, for this project, bringing an apple for the teacher is perfectly ok.


This project is easily completed at home or in the classroom. Educators can assign students to work on it at home and bring their results to the class. Or, divide them up into teams, pairs or the whole class can complete the experiment together.

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When we slice an apple open an enzyme reacts to being exposed to the air turning the flesh of the apple brown. This reaction is called oxidization. Molecules from the apple are being released into the air.

However, some common household items prevent oxygen from destroying our food. Or at least, it slows down the process.

Of course, we could always cover the apple, but that’s not always possible. For example, when we serve an apple salad, it can’t be covered the entire time.

This experiment will help determine which items in our cupboards we should use to keep our apple slices fresher, longer.

You will need:

1 apple

1 tablespoon milk + 1/2 cup water
1 tablespoon vinegar + 1/2 cup water
1 tablespoon lemon juice + 1/2 cup water
1/2 cup water

And you may also try these items, too.

1 tablespoon baking soda + 1/2 cup water
1/2 cup coffee
1 tablespoon vegetable oil + 1/2 cup water
1 tablespoon orange juice + 1/2 cup water
1/2 cup peppermint tea

Slice the apple into 5 slices if only using the first 4 ingredients. However, you will need one extra slice for each additional ingredient used in the experiment. Place each slice in a separate dish.

Set aside one dish as the control apple. In each of the remaining dishes, add one solution. Label the dishes (diagram1) with the matching solution.

Brown Apple Diagram

Use the form below to record changes in the apples. After the first 5 minutes, determine the best intervals to check the changes in your apples. Mark the changes you see in the boxes.

Brown Apples Chart

Brown Apples Experiment PDF

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