Studentsdiscover exactly how popcorn is grown and also explore the phenomenon of howpopcorn pops.Grades 3-5

materials Needed

Interest method – Engagement

Popcorn cob in a brown paper bag*, Jiffy popular music popcorn, or a bag of microwave popcornHot plate or microwaveUn-popped popcorn kernels, 1 per studentPopped popcorn, 1 item per studentHand lens (optional)

*These item are consisted of in the Popcorn top top the Cob! Kit, i beg your pardon is available for acquisition from hunterriverpei.comstore.com.

You are watching: When popcorn is heated over a flame, the kernel burst open. why does this occur?

Activity 1: Anatomy of a Popcorn Kernel

Un-popped popcorn kernel, 1 every studentPopped popcorn, 1 piece per student

Activity 2: trying out How Popcorn Pops

Safety glasses*2 check tubes 16 mm x 125 mm* (we tested PYREX® ignition tubes)4 boil stones*Centrifuge tube*Small balloon*Test tube clamp*Heat-resistant glove (genuine leather, cooktop mitt, food preparation glove, etc.)Alcohol lamp*Denatured alcohol (fuel because that the alcohol lamp)Multi-purpose lighterVegetable oil*, 1 dropUn-popped popcorn kernel*Aluminum foil*Test pipe stand or glass containerCircle-shaped difficult notes or circle-shaped record die-cuts, 8 every groupPlaydough, 1 handful per student

*These items are contained in the gain Popping! Kit, which is easily accessible for acquisition from hunterriverpei.comstore.com.

Activity 3: Popcorn Nutrition

Nutrition labels from assorted snack foodsAir-popped popcorn, 3 cupsStick that butter
Essential papers (maps, charts, pictures, or documents)
Vocabulary words

combine: a maker that cuts crops and also separates the seed from the remainder of the plant, combine the harvesting, threshing, and also winnowing processes

Corn Belt: the area of the United says where corn is the predominant crop grown

endosperm: tissue formed within a seeds that contains energy (starch) and protein because that the germinating seed

germ: the embryo that a cereal grain seed

germinate: to begin to grow; sprout

grain: the edible seed or seed-like fruit the grasses that space cereals (such as wheat, corn, and also rice)

pericarp: the outer, protective extending of the corn kernel

pollination: the carry of pollen from the anther come the stigma of a plant; the dispersing of pollen by insects, birds, bats, and also the wind between flowering plants

whole grain: has all 3 edible components (the endosperm, bran, and germ) in the same proportions as the harvest grain seed before it is processed

Did you Know? (Ag Facts) Popcorn have the right to pop together high as 3 feet in the air.1The peak period for home intake popcorn sales is in the fall.1Popping popcorn is among the most commonuses for microwave ovens. Most microwave ovens have a "popcorn" control button.1
Background agricultural Connections

This lesson is conveniently nested into a storyline together an episode trying out the phenomenon that popcorn popping. In this episode, students inspection the question, "How go popcorn pop?" save in mind the phenomena-based lessons incorporate storylines which arise based upon student questions. Other lesson to plan in the National farming Literacy Curriculum Matrix may be provided as episodes to inspection student concerns needing science-based explanations. For an ext information around phenomena storylines visit nextgenstorylines.org.


Popcorn is a "New World" food—it source in the Americas and was unknown in the eastern continents till after the trip of Columbus. Just since it"s dubbed a "New World" food doesn"t mean it"s very brand-new at all. In fact, the oldest ears the popcorn ever uncovered were discovered at Bat cavern in west main New Mexico and also are assumed to be roughly 5,600 year old.2 aboriginal tribes indigenous North and South America relied on popcorn as an essential food staple but additionally used it as a decoration. Cortez detailed this in 1519 once he come into contact with the Aztecs, who used it to create exquisite decorations choose ceremonial headdresses, necklaces, and ornaments ~ above statues.

Americans this day consume 13 exchange rate quarts that popcorn eachyear,more than any type of country in the world.3 13 billion quarts averages the end to around 42 quarts (40 L) or 10.5 gallons per person. Imagine10.5 gallon milk containers full ofpopcorn because that every human being in the unified States.That"s a most popcorn!The majority of the popcorn consumed global is get an impressive in the Corn Belt of the United says covering Iowa, Illinois, Indiana, southerly Michigan, west Ohio, eastern Nebraska, east Kansas, southern Minnesota, and Missouri. Nebraska is the optimal producer of popcorn.

Popcorn is a type of maize (corn) scientifically recognized asSea mayseverta.There are 5 different varieties of corn—sweet corn, popcorn, dent (field) corn, flour corn, and flint corn—but just one kind that pops...popcorn! Popcorn seeds room planted in the spring and take 7-10 days to germinate. The plant can grow to about 8 feet high and produce ear of corn covered in a green husk. Popcorn plants room wind pollinated. The pollen is located in the tassels at the top of the plant. The ears type silks that catch the pollen together the wind blows. The pollen travels down a smalltube in each silk and fertilizes the ovule at the base. After effective fertilization, a kernel develops and the silk detaches.

The popcorn is prepared to harvest once the kernels becomehard and the stalk and leaves the the plant are brown and also dry. Typically, a combine is used to harvest the popcorn. The ears space strippedfrom the stalk, and also the kernels are shelled indigenous the cob in the combine. The kernels room transported come a warehouse bin where they room dried till they reach the best moisture level that 14%. The kernels room then cleaned, polished, and also packaged because that distribution.

Popcorn is a grain composedof three parts—thepericarp (hull),germ, andendosperm. The pericarp is the difficult outer shell neighboring the popcorn kernel. Inside the kernel is the germ, or seed embryo, and the endosperm. The endosperm has trapped water and starch, i beg your pardon serves as food for the embryo during germination.

The popcorn kernel will certainly pop as soon as it is heated to aninternal temperature that 400-460°F (204-238°C). As soon as the kernel is heated, the moisture in the endosperm starts to boil and also turns to steam. Due to the fact that the pericarp is hard, pressure builds up inside the kernel. The starch gelatinizes and also the humidity vaporizes till the pressure inside the kernel get 135 pounds every square inch. At this suggest the kernel to explode open and also the starch solidifiesto kind the white, puffy part of popped popcorn. Together the kernel turns inside out, the steam escapes.

One offer of popcorn provides about 70% the the encourage individual daily intake of whole grains. Popcorn also containsfiber, iron, and also a number of essential vitamins. Per cup,popcorn includes 31 calories once air-popped,55 calories when oil-popped,and 133 calories as soon as lightly buttered. Popcorn is a healthy and also nutritious whole grain snack option.

Interest technique - Engagement present the classthe popcorn cob. Ask them if they understand what sort of corn the is? (If you execute not have actually a popcorn cob, present the course a container that Jiffy pop popcorn or a bag that microwave popcorn. Ask the college student what lock think is within the packaging.)Give each college student an un-popped popcorn kernel to observe.
With yourstudents, pop popcornright off the cob. Location the cob in a record bag, fold the optimal of the bag down twice to secure the top, ar in the facility of a microwave, and heat on high power for 1-1/2 to 3-1/2 minute (time will certainly vary with the wattage that the unit). Prevent the microwave when quick popping slows to 1-2 seconds in between popping. Very closely open the bag. The cob is really HOT! Note: some kernels may not pop because of uneven heat distribution in the microwave. (If you room popping Jiffy popular music over a warm plate or microwave popcorn, follow the directions on the packaging.) ask the students to describe what lock observe. Discuss the heavy steam that is presentthe moment the bag is opened.Give each college student a item of the popped popcorn come observe. Questioning the student what distinctions they observe in between the un-popped and popped popcorn.Ask the students, "How does popcorn pop?" ~ hearing your responses, let them recognize that this is a phenomenon precious investigating.

This lesson investigatesthe phenomenon that popcorn popping. Herbal phenomena space observable events that happen in the universe that we deserve to use our science understanding to define or predict.

Phenomenon-Based Episode: How walk Popcorn Pop?Disciplinary core Ideas: Structures and also Properties of MatterNational AgriculturalLiteracyOutcome Theme:Food, Health, and Lifestyle

QuestionScience and Engineering PracticesStudent Engagement in PracticesExplanation
What is a popcorn kernel made up of?Obtaining, Evaluating, and Communicating InformationStudentsobtain, evaluate, and communicate information about the parts of a popcorn kernel.A popcorn kernel is made up of three parts—the pericarp, germ, and also endosperm. The pericarp is the hard, external shell bordering the kernel. Within the kernel is the germ, or seed embryo, and the endosperm. The endosperm has trapped water and starch.
Whathappens to water when it is heated?Planning and Carrying the end InvestigationsDeveloping and also Using ModelsStudents lug out investigations and develop models to discover what happens to water as soon as it is heated.As water is heated and reaches the cook point, it alters from a liquid to a gas (steam). The molecule in the heavy steam move apart and also take increase any accessible space.
Whathappens to the water within a popcorn kernel as soon as the kernel is heated?Planning and also Carrying out InvestigationsEngaging in dispute from EvidenceStudents carry out investigationsand communicate in discussion from evidence to explore and explain what happens to the water within a popcorn kernel when the kernel is heated.As the kernel heats up, the water inside boils and also turns to steam. Due to the fact that the pericarp is hard, pressure from the heavy steam builds up within the kernel. The pressure eventually becomes so great that the kernel bursts open.
How does popcorn pop?Engaging in discussion from EvidenceConstructing Explanations and Designing SolutionsStudentsengage in debate from evidence and construct explanations to describe how popcorn pops.As the kernel heats up, the water within boils and turns right into steam. Because the pericarp is hard, push from the steam builds up inside the kernel. The starch gelatinizes and also the pressure eventually becomes so an excellent that the kernel explode open, and also the starch solidifies to form the white, puffy part of the popcorn.

Activity 1:Anatomy the a Popcorn Kernel (Episode inquiry 1)

Ask the student to discuss the following question with their group, "What do you think wake up to popcorn before, during, and after popping?"Instruct the studentsto recordtheir principles in the suitable sections that the graphic organizer. Allow time because that each group to re-superstructure their principles with the class.Explain come the students the in order to understand just how popcorn pops, that is beneficial to know more about the components ofa popcorn kernel, just how it is grown, and also how it differs from other varieties of corn.Choose native the following choices to examine just how popcorn is grown and also the parts of a popcorn kernel.Place the students earlier into your groups, and allow time for them to include to, revise, and/or question their original concepts on your graphic organizer. Share any type of additions, revisions, or inquiries with the totality group.

Three Dimensional finding out Proficiency: Crosscutting Concepts

Students connect different domain names of science fields into a coherent and also scientifically-based see of the world.

Structure and also Function:The way an thing is shame or structured determines many of that properties and also functions.

Activity 2: experimenting How Popcorn mr (Episode questions 2-4)

Safety Notes: There space risks associated whenusingan open flame and also glass test tubes.Consider reviewing the acquire Popping! videobefore you demonstrate this task with the students.The following safety actions should it is in practiced as soon as performing the investigate in Activity 2:

Roll up lengthy sleevesTie ago long hairWear safety and security glasses (everyone in the room)Keep occupational area clearInspect the test tubes for cracks or damage (do not usage the test tube if it is damaged)Make certain that the test tube glass is at room temperature before beginning the demonstrationKeep the check tube opened pointed far from yourself and also studentsStudents have to be at the very least 15 feet far from the demonstrationStudents should have actually observed vapor as component of theInterest approach – Engagementactivity. Ask the students, "How is steam created?" (Steam is developed when water is heated and also liquid transforms to gas—water vapor. When water vapor meets the cooler air, it condenses into tiny water droplets exposed in air—steam.)Ask the student to think about how to design an experiment to watch water changingto vapor using a test tube, water, a balloon, and a warm source. Discuss their ideas and guide the class until lock come up v a procedure similar to the following.Put on safety glasses. Place four boiling stonesinto a check tube. Use the centrifuge tube to measure up 3 mL of warm water, and also pour the water right into the check tube.Safety Note: To prevent boiling water beginning the balloon and spraying out when the balloon pops, execute not to fill the test tube an ext than recommended. If boil water begins to enter the balloon, immediately remove the test tube from the heat.Stretch the end a small balloon by punch it increase a couple of times, and also then large the balloon opened over the peak of the check tube, pulling the balloon under over the optimal one inch of the tube. Irradiate the alcohol lamp, placed on a heat resistant glove, and use a test tube clamp to host the test tube over, but not straight in, the fire of an alcohol lamp. Warm the water in ~ a slight angle. Questioning the students come predict what lock think will occur asthe water heats up.
It will certainly take about 45 seconds-1 minute for the water to start to boil. At this point, hold the test tube straight up to enable the steam to get in the balloon. As the water get the cook point, questioning the students, "What are you observing?"(The water is transforming to steam.The steam is expanding and also trying to escape, inflating the balloon with its pressure.) asking the students to predict what lock think will take place to the balloon and why. (Eventually, the vapor will create enoughpressure come explode the balloon.) It will certainly take around 1-1.5 minutes for the balloon come inflate and about 1.5-4 minute or much more for the balloon to pop.Extinguish the lamp"s flame and place the warm test pipe in a test pipe stand or glass container come cool.Ask the students to diagram what castle observed. Use the college student diagrams to explain that all issue is comprised of tiny parts called molecules. The plan of molecules differs in solids, liquids, and also gases.Model the arrangement of molecules in solids, liquids, and gases using among the adhering to options.Have the students do fists v their hands, and also push your fists tight with each other to demonstrate that the molecule in solids space tight together. Have the students obstacle their fists lightly with each other to show that molecules in liquids pole together, however can relocate around. Questioning the students come think around what the heavy steam was doing within the balloon, and also use their fists to show molecules in gases. The students should relocate their fists almost everywhere the place to demonstrate that molecules in gases move apart and take up any easily accessible space.Place college student in little groups and administer each group with 8 circlesticky notes. Have actually the college student arrangethe stickynotes so that they are poignant each various other tightly together to show that the molecules in solids room tight together. Have the students arrange the sticky notes so the they are lightly emotional each other to demonstrate that molecule in liquids stick together, but can relocate around. Asking the students to think about what the vapor was doing within the balloon, and also use the difficult notes to demonstrate molecules in gases. The groups should arrange the difficult notes so the they room not poignant each other and also taking up as much space as feasible on the desk to show that molecules in gases move apart and also take up any obtainable space.Provide each student v a grasp of playdough. Asking the student to do 8 little balls that dough. Have the college student arrange the playdough balls so that they are emotional each various other tightly to demonstrate that the molecule in solids room tight together. Have the students arrange the playdough balls so the they are lightly touching each various other to demonstrate that molecule in liquids pole together, however can relocate around. Ask the students come think about what the vapor was doing inside the balloon, and use the beat dough balls to show molecules in gases. The students must arrange the playdough balls so the they space not touching each other and taking up as much room as feasible on the desk to demonstrate that molecule in gases move apart and also take up any accessible space.After modeling the molecules in solids, liquids, and gases,ask the students to describe how the steam made the the balloon expand and eventually burst. (As the water was heated and changed from fluid to gas(steam), the molecules in the steam moved personal to take up any obtainable space, filling up the balloon and also eventuallycausing sufficient pressure to burst it.)Review the parts of a popcornkernel, and
repeat thestudents that popcorn kernelscontain water. Ask them come predict and also explain what will occur if a kernel the popcorn is heated in a check tube.After hear the predictions and explanations, put on safety and security glasses, place one kernel the popcorn and a fall of vegetables oil in a dry test tube, and cover the peak of the check tube v aluminum foil. Placed on a warm resistant glove, and also use a test tube clamp to hold the test tube over the alcohol lamp flame. Shake the test tube to prevent burning the kernel. (Keep the top of the test tube pointed far from you and also the students!) It will take about 45 seconds-1 minute because that the kernel come pop.Extinguish the lamp"s flame and also place the hot test tube in a test pipe stand or glass container come cool.Clarify the each kernel the popcorn includes water stored inside a one of soft starch. Questioning the students to explain what they observed. (As the kernel heats up, the water within the kernel boils and turns into steam. Due to the fact that the pericarp is hard, press from the heavy steam builds up within the kernel. The strength gelatinizes and the pressure eventually becomes so good that the kernel to explode open and the strength solidifies to type the white, puffy part of the popcorn.)Ask the student to usage their fists to show the water molecules inside thepopcorn kernel, and then the steam molecules as soon as the kernel to be heated.Place the students ago into their teams from Activity 1, and enable time because that them to add to, revise, and/or concern their original ideas on their graphic organizer. Share any kind of additions, revisions, or questions with the totality group. Questioning the students to share just how their thinking readjusted and why. Usage the perfect graphic organizers come evaluate student understanding.
If you put a cob the sweet corn in a microwave, will the kernels pop prefer popcorn? It"s essential to understand that various corn arrays are grown to satisfy various food and also production needs. There are 5 different varieties of corn—dent corn, sweet corn, popcorn, flour corn, and also flint corn—but only one type that pops...popcorn! Sweet corn will certainly not popular music because, unequal popcorn, the kernels perform not have actually a hard pericarp or the right moisture level inside. Watch the great Corn: one A-maizing Plant: Food, Fuel, and also Plastic for more information around the various varieties that corn.

Three Dimensional Proficiency: Crosscutting Concepts

Students link different domain names of science fields into a coherent and also scientifically-based watch of the world.Cause and also Effect:Events have causes, occasionally simple, periodically multifaceted. Deciphering causal relationships, and the mechanisms whereby they space mediated, is a significant activity that science and engineering.

Activity 3: Popcorn Nutrition

Have the students bring in nutrition brand from your favorite snacks. Compare and contrast calories,fat, sugar, and also vitamin content. Heat the labels up in order of calorie content. Reorganize the labels in bespeak of street content. Repeat through fat content. Questioning the students to determine which snack food is healthiest overall.
Put 3 cups the air-popped popcorn into a bowl, show it come students, and also writethe calorie contents (93 calories) on the board.Hold increase a rod of butter and also write thecalorie content (810 calories) top top the board. Questioning the students, "If you added one stick of butter come the popcorn, how many calories would that be in total?" (903 calories)Remind students that they must be responsibility of the calories when adding butter come popcorn. That is possible to turn a healthy and balanced snack into an too many caloric "junk" food item.Explain come the students that popcorn is a whole grain, an interpretation it includes the whole whole serial kernel—the bran, germ, and endosperm. In contrast, a polished grain has actually been milled to eliminate the bran and germ i m sorry contain much of the diet fiber, iron, and B vitamins. Popcorn can aid you fulfill the referral to "make half of your grains whole."Share the following popcorn nutrition facts through the students:Per cup, popcorn consists of 31 calories once air-popped, 55 calories when oil-popped, and also 89calories as soon as lightly buttered.Popcorn is a entirety grain. It provides energy-producing complex carbohydrates.Popcorn consists of fiber, giving roughage the body requirements in the everyday diet.Popcorn has no artificial additives or preservatives and also is sugar-free.Popcorn is best for between-meal snacking due to the fact that it satisfies, however doesn"t spoil, the appetite.Three cups of popcorn equates to one offer from the serial group.

See more: Why Are Pringles So Addictive And How Many Pringles Are In A Can ?

Concept Elaboration and also Evaluation

Ask the student the complying with questions:Does vapor have energy? (yes)What proof do we need to indicate that steam has energy? (Steam inflated and also burst the balloon. Steam caused the popcorn kernel come pop.)Review and also summarize the following key concepts:Popcorn is a serial composedof 3 parts—thepericarp,germ, andendosperm. The endosperm contains water and starch.When water is heated, the water turns from a liquid to a gas—steam. Gas molecules relocate around and take up any obtainable space.When a popcorn kernel heats up, the water in the endosperm boils and turns right into steam. Pressure from the vapor builds up within the kernel, eventually ending up being so good that the kernel bursts open.Popcorn is a healthy and also nutritious whole grain snack option.