Ice Cream Matters!

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Student worthiness
Tried at least once and worked well.

Primary biological content area covered: States of Matter
During this experiment, students will study "States of Matter" because they will experience liquid freezing into a solid. While observing the freezing, they will learn about the point at which liquids freeze: freezing point. We will explain to the students that energy is required to melt the ice. When we mix the rock salt and ice together the salt begins to dissolve. The mixture gets energy to dissolve the salt by removing heat from the ingredients baggie. It is a mistake to double bag the baggie because the extra insulation prevents freezing. The energy that is used to dissolve the salt is also used to freeze the ice cream.

Materials
Each group of two or three needs:


 * One plastic jar
 * 4 oz. of Half and Half
 * 16 oz. of rock salt
 * 40 oz. of ice
 * A small plastic zipper bag
 * 2.5 oz. of sugar
 * Thermometer
 * 1/4 teaspoon
 * One tablespoon
 * One cup
 * 1/2 cup
 * Plastic cups/ bowls/spoons (to eat the ice cream!)

Optional Materials:


 * Sprinkles
 * Flavoring (mint extract, vanilla, raspberry extract, chocolate syrup: measure 0.125 oz. of flavoring and add to plastic baggie of ingredients)
 * Gloves for the students to wear while shaking the containers.

Handouts

 * The following handouts are resources for the students to understand how to make ice cream and answer questions containing what is happening scientifically while they are making their ice cream.

Description of activity
At the beginning of this experiment, students will be split up into groups of two or three. Each group of students will receive a large, plastic cylinder and small baggie (see materials) to make their ice cream in. The rest of the materials will be shared by all the groups. Students will create their own ice cream by combining all ingredients (besides the ice and salt) in the small baggie. The small baggie will be placed in the cylinder. The salt and ice will then be added to the cylinder, surrounding the small baggie. Once ingredients have been combined, students will shake their cylinder (note: cylinder must be shaken vigorously to get hard ice cream fast!). The ice and salt combined will make the ingredients in the baggie freeze and this will create ice cream!

Lesson plan

 * Divide students into groups of two or three depending on what flavor of ice cream each student wants.
 * Distribute a small baggie to each group.
 * Set out the rest of the ingredients to be shared amongst the students.
 * Students will create their own ice cream by combining all ingredients (besides the ice and salt) in the small baggie; set the baggie aside.
 * Next add 16 oz. of ice in the bottom of cylinder and 8 oz. of rock salt; place small baggie inside cylinder.
 * Add 16 more ounces of ice, 8 more ounces of salt, and top with 8 more oz. of ice.
 * Shake cylinder vigorously for about 5-10 minutes (may want to check after two or three minutes to make sure fluid in baggie is getting harder; if it is not you may want to add more ice and more salt)
 * VOILA! You have ice cream!

Potential pitfalls

 * Potential pitfalls could be that we do not use the correct amounts to make enough ice cream for each student. It may also be difficult to explain how the salt and ice combination creates the ice cream. In addition, it may be difficult to connect this experiment with other subject areas.
 * For this experiment you need a large amount of ice and rock salt. We ran out of rock salt with one group left so we had to use the excess ice and rock salt combination from the previous experiments. We also would have run out of ice if we didn't have an ice maker available.

Math connections
Students will be asked to identify and use different measurements when measuring the ingredients. Students will also need to measure the temperature of the ice and do some quick math to determine the difference in temperatures.

Health connections
This activity can easily be used to help students understand the new food pyramid. Comparing the old food pyramid to the new pyramid, and noticing the differences in the two will help students understand what the world has learned about nutrition and healthy lifestyles. The changes in the size of the dairy section between the two food pyramids is something that would be good to point out to the students, if they do not point it out themselves. It is also good to make sure that students understand why the section that included sweets is no longer a part of the food pyramid. Students need to understand that when it comes to fatty and sugary foods, they are okay to eat in small quantities every once in a while, but not every day. The new food pyramid also emphasizes an active life. This can be carried over into the classroom by having the students participate in learning activities that involve being physically active.

Literature connections
During this experiment, students will be required to reflect on the experiment and write about what they learned while conducting this experiment. This is a literature connection because students will be writing during the experiment. In addition, students can read or glance through the book, "Solids, Liquids and Gases (Starting with Science)" by Ontario Centre.

Connections to educational standards
S3-4:12 (DOK 2) Students demonstrate their understanding of the States of Matter by…


 * Identifying, describing, and comparing the properties of selected solids, liquids, and gases.

S 3-4: 2 (DOK 2) Students demonstrate their understanding of PREDICTING AND HYPOTHESIZING by…


 * Identifying simple patterns of evidence used to develop a prediction and propose an explanation.

S3-4:4 (DOK 2) Students demonstrate their ability to CONDUCT EXPERIMENTS by…


 * Referring to and following a detailed plan for an investigation AND
 * Clearly describing evidence and quantifying observations with appropriate units AND
 * Recording data at various points during an investigation by reporting what actually happens, even when data conflicts with expectations AND
 * Recording the sequence in which events take place AND
 * Recording relevant details of an object and its surroundings when applicable AND
 * Drawing scientifically:

a. Recording varying degrees of color, shading or texture, and consistent proportion throughout

b. Labeling significant parts of a scientific drawing or diagram and including a key if necessary.

Next steps
Following this experiment the students could try making various flavors of ice cream using materials such as raspberry extract and peppermint! For a math connection you could then make a classroom graph displaying how many people chose each flavor and which flavor portrays the maximum, minimum, and median of the data.

Reflections
Olivia's Reflection:Overall, this experiment went really well. Many of the students had previously completed this activity, and all of them knew that they were going to be making ice cream before we said anything to them, but it didn't prevent them from being interested in the process and asking good, thoughtful questions. I was very pleased that we were not asked any questions that at least one of us didn't know the answers to. As a group, we demonstrated good teamwork skills which I believed helped in the efficiency of the experiment and the final outcome. Having students that knew the process was helpful because they helped to explain to their peer what the steps were and what was happening. We did a much better job preparing for this experiment than we did for our previous experiment and this was shown in how flawlessly we were able to not only complete the experiment but also replicate it six times without a break in between. This experiment, like almost everything else, could have benefited from more time. If we had more time we would have been able to talk more about what was happening scientifically it possible for our half and half mixture to turn into ice cream. We also would have been able to touch on the new food pyramid and why foods like ice cream are ok to have as long as they are not eating it every day or in large quantities. It also would have been nice to have a bit more space to work in as it got a little crowded around the table with eight students and the three of us fighting for elbow space. However these are both areas that would be easier to accommodate for in our own classrooms. I am very glad that we did this experiment because it was rewarding to see the students' reactions to what they created. They were excited and engaged in the activity from the start to the finish, which I believe is one of the main goals of a teacher in any lesson.

Lindsay's Reflection:I found that this experiment was a great success for us as the teachers and also the students. Our group was much more prepared for this experiment than our first one. We practiced the experiment a number of times so we knew what proportions of ingredients would work best. We knew we couldn't risk a student not receiving any ice cream so we had to get them exact. We also started out double bagging the plastic bags to omit the possibility of and leaks. We then found that this slowed the process dramatically so we decided to only use one bag. Its simple decisions like this that made our experiment go very smoothly. It's clear that we all learned a lot about running the experiment with this age group. This is a noisy experiment when the students are shaking the canisters so it was good to be in a secluded area so we wouldn't be disturbing people around us. If we were to do this again I would supply gloves for the students because they were only able to shake the canister for a very short time due to the cold temperature. I was surprised at how well this activity fit the time available. The students would just be finishing eating their ice cream when the twenty minute period would be over. If we were allowed more time however, we would have been able to go over how and why the process works in more detail. The students saw the Hershey's Syrup and got so excited about making the ice cream that they were not focused on the scientific aspects of the experiment.

Heather's Reflection:With this second experiment, I feel that our group made a huge leap forward regarding deciding on an experiment, preparation, and actually conducting our experiment. Since we now had experience from our first science experiment with kids, we knew we wanted to do an experiment that would be more fun, which is why we decided to make ice cream and address states of matter. We thought our experiment would be easier than what actually happened. As we began to test our experiment, it took a long time to get it perfect to bring it into the classroom. We had to test our experiment four or five times, changing the quantities of ingredients, especially the rock salt and the ice each time. We had to change the quantities because our experiment was longer than 20 minutes. We had to change our procedure a lot by not double bagging because it was taking to long for our ice cream to freeze and instead of throwing the bag of ingredients on top of the ice and rock salt, we realized we needed to layer the ice and rock salt and place the ice cream baggie in the middle of the mixture so it can be surrounded with ice and rock salt. Once we did that we were getting hard ice cream instantly. We also had problems with the worksheet again in this experiment. I feel that 20 minutes to conduct an experiment and adequately explain and complete a worksheet is not enough time. In addition, I feel that the kids were really excited to make ice cream, but they did not pay attention when we were trying to explain what is happening during the experiment scientifically. To improve this experiment, I think it would be beneficial to keep the materials hidden while we teach a lesson about the effects of rock salt on ice. Once they learn what is happening scientifically with those ingredients, we would take out the other materials and make the ice cream. However, this strategy would only work if we had more than 20 minutes because it takes that long to make the ice cream.

Citations and links
Centre, Ontario Science. Solids, Liquids and Gases (Starting with Science). New York: Kids Can,, 2005.

"Virginia T. O'Brien - Higgins Community Academy." Illinois Institute of Technology | Office of Technology Services. Web. 19 Feb. 2010. &lt;http://mypages.iit.edu/~smile/chbi9914.htm&gt;.