real science for today's homeschooler

Using Popcorn to Practice Scientific Method

Using Popcorn to Practice Scientific Method

This is a fairly common science fair project that I actually helped my grandson carry out for an elementary science fair. It’s definitely not a new idea, but a great way to let children work through the scientific method using a fun topic . . . POPCORN! The question to be answered is: “Does storage temperature affect how well popcorn pops?” Children will be storing popcorn in a warm environment, room temperature, cold, and frozen. Before beginning the experiment, encourage students to make a Hypothesis. Ask them to decide which storage method they think will work best, and why.

Materials: large bag of loose popcorn (not the individual “flavored” bags), baggies, paper lunch sacks, access to a microwave

Here’s the procedure we used, but it’s important to let your child come up with the procedure if this is to be a scientific method experiment.

1. Put 100 popcorn kernels in a plastic baggie and label as “warm.” Repeat with 3 more baggies, labeling them as “room temperature,” “cold,” “frozen.”

2. Place the baggies in the appropriate area. For example, store the “warm” bag under an electric blanket, the “room temperature” bag in the pantry, the “cold” bag in the refrigerator, and the “frozen” bag in the freezer. Select a specific time for storage, such as a week, a month, etc.

3. After the storage time is complete, remove the bags from their storage area at the same time. To test the storage methods, divide out the 100 popcorn kernels between 5 paper lunch sacks, with 20 kernels in each bag. Label each paper sack with the appropriate storage method. Repeat with all the remaining popcorn, being sure to label each paper sack with the correct storage method!

4. Decide on a specific popping time. Somewhere around 2 minutes works best, but any time will work if it gives the popcorn time to pop and you keep the time the same for all trials.

5. Put one of each sack of popcorn into the microwave at the same time. (In other words, place one sack that contains popcorn stored as “warm,” one sack with “cold” popcorn, etc. Turn on the microwave for the specified time. After the time has elapsed, remove the bags and count the number of kernels that popped. Record. Repeat until all the popcorn has been tried.

Data: Here’s a sample data table that can be used to record the results. For older children you may want to let them design their own table.

  Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Average
warm            
room            
cold            
frozen            

 

Older children can find the average of each type. For younger children who may not understand the concept of averaging, change to “Total” for the last column.

Analysis: Younger children can compare the totals to see which storage method resulted in more popped kernels. Older children can graph the results for a visual representation.

Conclusion: Have students state out loud, or write down, which storage method produced the most popped popcorn. Why do they think this method worked best? Also have them refer back to their original hypothesis. Was their hypothesis right or wrong?

HINT: Based on experience, don’t try to pop one bag at a time in the microwave. There will not be enough water in the popcorn to absorb the microwaves and the appliance will overheat! Mine actually stopped working for awhile! Popping four bags at a time worked well for us, but do feel the sides of the microwave after the first round to make sure it isn’t overheating. Take breaks between rounds if needed.

ALTERNATE METHODS: Children can also come up with their own idea of what to test, such as light vs dark, storage time, type of storage container, etc. The more children are able to make the experiment their own, the better!

BACKGROUND: Depending on the age of your child, You may also want to have them research WHY popcorn pops. Here’s a great website that explains the science of popcorn, as well as some interesting history: http://www.popcorn.org/Facts-Fun/What-Makes-Popcorn-Pop.

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Seed Germination Lab

Seed Germination Lab

Children are fascinated by the fact that a seed can grow into a plant. You’ve probably already planted seeds with your child in order to watch them grow into plants. Here’s a slightly different way to show your child the actual process of germination that allows them to actually see the plant emerge from the seed.

Materials: seeds, paper towel, plastic sandwich bag, magnifying glass

Procedure:

1. Fold a paper towel so that it fits flat inside a plastic sandwich bag.

2. Soak the paper towel thoroughly with water. You want the towel very wet from end to end, but not dripping with excess water. Place the paper towel in the bag and lay flat.

3. Place seeds on the paper towel so that they are spaced out away from each other. Press each firmly into the wet paper towel. (Hint: Although any type of seed will work, small, fast-germinating seeds work best. Whole birdseed such as millet works very well.)

4. Seal the baggie to conserve water and place the bag in a place where it will be undisturbed.

5. Gently slide the paper towel out of the baggie each day and observe the seeds with a magnifying glass. Depending on the type of seed used, you should start to see the seeds germinate within a few days to a week.

6. Between daily viewings be sure to gently replace the paper towel into the baggie and reseal. Re-wet the paper towel if it begins to dry out. You should be able to germinate the plants long enough to see the first leaves develop.

Lab Variations:

  • When the seedlings begin to produce leaves, transfer to soil and continue to grow into a larger plant.
  • Prepare more than one baggie with the same type of seed. Place the baggies in different environments (temperature, sunlight, etc.) to see how environmental factors affect seed germination.
  • Prepare more than one baggie with the same type of seed. Put differing amounts of water into each baggie to see how different amounts of available water affect seed germination.
  • Prepare more than one baggie using a different type of seed in each. Compare germination times of different types of seeds.
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Leaf Prints – Science meets Art!

Leaf Prints - Science meets Art!

Use an old standby in kids art projects to teach some plant science!

The Art

Remember making leaf prints when you were a kid? Here’s a short procedure:

1. Collect a variety of fresh, green leaves.

2. Provide a large sheet of clean paper. Thin paper works best. You’ll also need some old crayons with the paper peeled off.

3. Place a leaf under the paper. Use the side of the crayon to rub across the paper above the leaf. An impression of the leaf will appear. Encourage your child to push down hard enough to make the stem, veins, and outer edges visible.

4. Continue printing different leaves with different colors to create a collage of leaf prints!

The Science

Okay, so where does the science come in? Use the image below to help your child identify the parts of the leaves on their collage. They can label one or all of the leaves with the different parts.

leaf-parts Explain to your child that the veins in a plant are similar to the veins in an animal. They are used to transport materials throughout the organism. Plant veins are different from animal veins in that they carry water instead of blood.

You can also have your child identify the basic shape of different leaves by comparing the leaf prints to the diagram below:

leaf shapes 2

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