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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How do you rate in general Scientific Knowledge?

How do you rate in general Scientific Knowledge?

Here’s an interesting Science Quiz done by the Pew Research Center. It contains some basic science knowledge questions in multiple choice format. Take the quiz and then see how you score against average American adults. You can also find overall results based on demographics. Follow another link to check out the full analysis of the poll that was designed to discover, “What the Public Does and Does Not Know About Science.”

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Yeast – Examining Living Cells

Yeast - Examining Living Cells

Yeast . . . it turns grapes into wine . . . it makes bread rise . . . but did you know it’s actually a living one-celled fungus? Yeast provides a safe way for children to observe a few of the life processes of living cells.

1. Living Cells Need Water – Add dry yeast to very warm water to activate them. Explain to children that the yeast must have water in order to carry out life processes. They are able to survive in a dormant state without water, but they won’t become active and grow until they have water.

2. Living Cells Need Food – Put some of the hydrated yeast culture in two small containers (preferably clear). Add sugar to one of the containers, but not to the other. Let children observe the differences they see over time. Does “feeding” the yeast cells make them more active?

3. Living Cells Produce Waste – The yeast culture with sugar will give off noticeable amounts of carbon dioxide gas in the form of bubbles. Explain to children that the cells are getting rid of waste just like they do . . . by “breathing” out carbon dioxide gas.

4. Living Cells Reproduce – If a microscope is available make a slide from a drop of the yeast culture with sugar. Look carefully and you may find a cell that is undergoing “budding.” Budding is the way yeast cells reproduce. First they double all the material inside the cell that’s needed to keep it alive. Then they separate out one set of the material and pinch it off in a little pocket on the side of the cell. The new pocket will eventually pop off and form a new yeast cell! Children enjoy seeing the “baby” yeast cells. 🙂

Extension – Make bread or another pastry that requires yeast to make it rise. Ask children to use what they have learned about the yeast cells to explain what is happening inside the dough. (The yeast is eating the sugar and using the water in the dough to grow. As it grows it produces waste in the form of carbon dioxide gas. The gas bubbles are what makes the bread rise. As the yeast reproduces, more and more yeast cells can produce more and more gas bubbles and the dough gets bigger and bigger!)

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Backyard Ecology

Backyard Ecology

No matter whether you live in the country or the city, your child can observe nature close to home. Help your child be a nature detective to discover the ecosystem existing right in their own backyard.

First, help your child identify what types of plants and animals they are realistically likely to see. If you have land in the country they’re likely to observe large mammals such as deer and racoons. If you have a tiny backyard in the city, help your child realize that they will be looking for small animals such as insects, lizards, birds, etc.

Depending on the age and interest of your child, prepare a plan to capture an image of the plants and animals they find. A digital camera works well, but if your child likes to draw they can turn the ecosystem hunt into an art project.

Over a span of a week or two, sit quietly outside with your child and observe nature. Have them find as many different plants and animals as possible. To find some of the more shy animals, help your child turn over rocks and other objects in the yard or on the porch. Try observing at different times of day, and even go outside with a flashlight at night to find animals that come out after dark.

For younger children you may just want to print out the photos and identify the different types of plants and animals found. They can make a collage or a notebook to display what’s living in their backyard. Older children may also want to research what each type of animal eats and design a food web based on that information. One method is to glue the images on a poster board. Then draw arrows going from the prey (or plant) to the predator. Older students can then examine their food web to infer other animals that might be a part of their backyard ecosystem that were never observed.

Whether you focus on the exploration or turn the project into an in depth ecology lesson, your child is sure to gain an appreciation for nature’s ability to sustain life anywhere!

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