Why Does Popcorn Pop?
Jennifer Martin-Kochis & Jennifer Washuta
For Mrs. Cutlerís 3rd Grade class
This mini-unit is an inquiry based science project that explores the question, "Why does popcorn pop?"
This mini-unit will develop the studentsí skills of prediction, observation and communication of scientific findings. These are essential skills for scientific investigation.
Students have eaten popcorn. Some may know that popcorn starts as a kernel and, when heated, explodes to form the popcorn that they eat. The students have learned that there are different types of corn. They have been developing the scientific skill of observation.
5.1, A.1. - Raise questions about the world around them and be willing to seek answers through making careful observations and experimentation (lessons 1-3)
5.1, A.2. - Keep records that describe observations, carefully distinguish actual observations from ideas and speculations, and are understandable weeks and months later. (lesson 1-2)
5.6, A.3. - Recognize that water, as an example of matter, can exist as a solid, liquid or gas and can be transformed from one state to another by heating or cooling. (lesson 2)
Give each student some popcorn (both popped and unpopped). Ask them to write/draw their observations of the popcorn in their journals. Then ask the question, "Why does popcorn pop?"
ASSESSMENT: -Student will label a diagram of a popcorn kernel.
ASSESSMENT: -Given a diagram of a popcorn kernel, students will create a hypothesis about why popcorn pops, using information provided during the
-high starch content in the endosperm
-endosperm contains moisture
-strong, hard hull
-Why does popcorn pop?
-Why do you think so?
Students Journals (1 per student)
Popcorn kernels, unpopped
Diagrams of inside of unpopped popcorn kernel (1 per student)
ASSESSMENT: -Students will write in their journals the observations they made of heated water.
-What did you observe?
-Why is this happening?
-Yesterday we learned that the endosperm, inside the popcorn kernel contains water. What will happen to this water when you heat the popcorn?
-Based upon your observations and our discussion today, do you need to change your hypothesis about why popcorn pops?
Cup full of water to be heated on hot plate
(Alternative - insulated cup containing hot water)
ASSESSMENTS: -Students will draw conclusions based on the observations they have made over the course of the investigation.
-Students will complete a worksheet about the sequence of steps involved in popping popcorn.
-Why didnít the cracked corn pop?
-Based on your observations today, do you need to change your hypothesis about why popcorn pops?
-What conclusions can you draw based on the observations you have made during this investigation?
Read The Popcorn Book by Tomie DePaola while students snack on popcorn.
Individualization - The journals are the students' personal records. There will be no rules for keeping them other than that someone else who wanted to review their research must be able to understand what their hypothesis is, what they observed, and what their conclusions are. They may use words, pictures and/or charts.