Adapted from a Lesson Developed by Janie Scronce
Determine three states of matter:
Observe changes in state due to heating and cooling in common materials.
- 1 popcorn popper (bubble popper is better so students can see process of
- 1 bottle of cooking oil
- 1 bag of popcorn kernels
- The Popcorn Dragon by Jane Thayer (William Morrow and Company;
- class set of sandwich bags with several unpopped kernels in each (1 per
pair of students)
- sandwich bag full of popped kernels
- Paper towels
- Drawing paper
- Crayons and/or markers
Hold up a bag with several popcorn kernels. Ask students a series
of questions such as what is this? How do you know? Have you ever eaten it?
Hold up a bag with several pieces of popped popcorn. Ask students
the same series of questions again.
Ask students if they know how popcorn goes from being a kernel
to a piece of popcorn. Have the students brainstorm ideas.
Read the story The Popcorn Dragon by Jane Thayer
- Distribute a sandwich bag of unpopped kernels to each pair of students.
- Have the students make as many observations about the kernels as they can
and write those in their science notebooks.
- Next, add oil and kernels to the popper and turn it on. (Remind students
not to touch the popper because it is hot)
- Have students record as many observations as they can about the popcorn
as it pops. What changes do they notice inside the popper?
- As they watch the popcorn pop: Inside each kernel is a tiny bit of water.
When heat is added to the water, what do you think will happen? Why?
- Give each pair of students a paper towel with some of the popped popcorn
on it. Have them record as many observations as possible about the popped
- Have students compare and contrast the unpopped kernels with the popped
Ask students questions about what they observed and learned from
exploring the kernels and popped popcorn and watching the popcorn actually pop.
Possible questions include:
- Now that everyone has made their observations what were some things that
you wrote about the unpopped kernels?
- What about the popped popcorn?
- Based on what we have learned about solids, liquids, and gases, which category
would you put the kernels in? What makes you say that?
- Describe what you saw as the popcorn popped.
- Based on your observations, can someone explain how they think the corn
changed from kernels into popcorn?
- How is what we did with the popcorn like what the dragon did to the popcorn?
- When was our popcorn a solid? What makes something a solid?
- Where was the liquid in our popcorn? What happened to it? Why?
- When did we see a gas during this activity? Why was it so important?
- How was the gas different than the liquid?
Inside of each peice of popcorn is a tiny drop of water. When
heat is added, the water changes from liquid into a gas (steam). When the pressure
of the steam becomes to great, the popcorn kernel bursts open to form a piece
Set several popcorn kernels out in the sun for several days and
then try to pop them.
- What differences do we observe in how the popcorn pops?
- Based on what we have learned about popcorn, what could explain the difference?
Teacher note: Setting the kernels in the sun will cause them to dry out. With
less water they will be difficult to pop.
- Have students draw a series of illustrations showing how the popcorn pops.
They should label a solid, liquid, and gas within their pictures.
- Have students write a written explanation of how the dragon was able to
cause the popcorn to pop including the words solid, liquid, and gas in their