This is a continuation from a lesson titled,"Science is 'Snow' Much Fun Part 1." In part 2, we made three snowmen from the "snow-dough" for an experiment. After making and decorating the snowmen the children formed a hypothesis based on their learning and observations from Part 1 about what they thought would make the "snow" melt faster--water, vinegar or air. Each child formed a hypothesis and wrote it down. Then as a class, we followed the other steps in the scientific method to complete the experiment--investigation, data collection and discussing the results.
For part 2 of the experiment, you will need the following:
Teacher Advanced Prep
In advance, cut 3 orange triangle noses out of craft foam pieces. Use a small paper punch for making 6 black eyes. Cut 6 small twigs about 2 inches. These will be used for the arms. When done, place the pieces for each snowman in its own plastic bag. You might also want a cover or tablecloth to cover the area you are working at, if you wish.
You may also make a hat for the snowman out of black craft foam. Originally this was in my plan, but it made it harder to measure the snowman accurately. It also prevented the water or vinegar from going down directly on the snowman. Therefore, I decided not to make the hats, but they are darn cute!
We review what happened in the previous lesson, Part 1.
Observation has a lot of power. Scientists rely on it everyday. Let's think back to yesterday's lesson. We made some observations about snow-dough using our senses. What kinds of things did you observe?
The children share some of their observations (see student video clip). I make sure they include each of the senses that we used. If not, I prompt them to do so.
I'm trying to get the children to create an explanation for what they have observed. This helps them make sense of their world, just like a scientist. In addition, I am also laying the groundwork for having the children plan and conduct an investigation to describe and classify different materials by their properties.
I write each of their comments on the Smartboard on a simple chart (Our Observations About Snow-Dough).
After discussing, I reply, "You sound just like scientists since scientists make observations to help them understand unknown materials! Good work, class!"
I also take the time to discuss the reaction the "snow-dough" had when we squirted vinegar on it. I ask if any of them had ever seen this before.
One child comments how her brother made a volcano for the science fair. She explains the experiment in detail. Her excitement builds as she is talking and the others are getting excited just listening to her. This is all part of activating prior knowledge. This helps the children make a connection to what we are learning to their past experiences. Others in the classroom learn from it as well.
I reply,"Your brother's volcano fizzed over the top because of a reaction between the vinegar and the baking soda. The combination creates carbon dioxide gas. When the gas escapes, it makes bubbles. The reaction always occurs when the two materials are put together.
I try to keep the explanation at a second grade level, but want to also include important details. I also want them to know that this reaction can be predicted since scientists have already made those observations.
Note: Our class is lucky to have someone with that experience so the children could relate to it. If you are not as lucky, you might want to prompt the children by asking if they had ever seen a volcano experiment where "lava" bubbles over the top. Chances are that they have. If not you could watch a quick video that shows this reaction. (Note: at about 4 minutes into the video is where the reaction occurs).
Next I have the children try to apply the concepts they learned from yesterday's lesson in a new context to build on their understandings. From the "snow-dough", we are going to make 3 snowmen for this science experiment. In doing this, we are in a primary way, developing and using models. Since we are doing this experiment as an entire class, I try to involve the most students that I possibly can. So I ask 9 volunteers to make the 1 ball each for the snowmen, just like they do with real snow. I call on other volunteers put together these snowmen in 3 separate pans. So the children make 3 snowmen out of three balls and place them each in their own pan. The "snow-dough" is kind of gritty, so I have the children wash their hands after they are done. They have a great deal of fun decorating the snowmen with eyes, stick arms and smile. The children make observations about the snowmen. We briefly share their observations.
Then I have the children think about what we observed yesterday when we put water and then vinegar on the"snow-dough."
I ask, "Thinking about what we did yesterday with the snow-dough, what do you think will make the snowmen melt faster--water, vinegar or doing nothing?"
I want the children to link their former observations and findings to a new situation which is a good foundation for scientific thinking. It also helps them develop skills needed for analyzing and interpreting data.
I pass out the Scientist Form Hypotheses Worksheet. Each child will fill out the worksheet to help them create their hypothesis. First we read the entire sheet together. When we get to a blank we say "blank" and continue reading. I find that continuing the flow increases their comprehension. Then we go back to complete the worksheet.
I ask the children, " What did the 'snow-dough' do when we added water to it?" They reply, "It melted." I inform them, " We call that dissolving. So write "dissolved" in the first blank." We repeat the same task but with vinegar. I have the children recall what happened when we added vinegar. They excitedly blurt out, "It fizzed!" So the children fill in the word "fizzed" in the next blank.
I ask the children, "Now I want you to use your own observations and knowledge to form a hypothesis about which liquid would make the snowman melt the quickest. You should discuss your ideas with your 8:00 clock buddy partner." (see My Clock Buddies Student Page and Directions).
I find that anytime we do writing, it helps to discuss it orally first. After they discuss their ideas with a partner, they circle one of the three choices--water, vinegar or nothing. Then they write down why they thought the way that they did. This is a beginning step for analyzing and interpreting data. (Click here for a student sample).
Then we set up our experiment. I commented to the children, "Scientists need to be very accurate with their experiments since they want to be able to recreate the experiment and have it work out the same each time. We call this consistency. We need to make sure we do the exact same thing to each of the snowmen, just varying the type of liquid we are testing. Therefore, if we deposit 2 tablespoons of water on the first snowman, then we must deposit 2 tablespoons of vinegar on the second snowman." So as a class we decide how much liquid we were going to put on the snowmen each time. The children decide that 2 tablespoons each "round" should be just right. We also decide we would do 3 rounds. A boy asks, "What is the third snowman was for?" I reply,"Snowman 3 is our control. We will do nothing to it to change it so we know if the liquids we put on it really are what is creating the changes."
Note: Measuring is part of the Common Core Standards, so adding it to my science curriculum is a double bonus! According to the standards, students should be able to measure the length of an object by selecting appropriate tools and be able to measure 2 objects to determine which one is longer. I practice both of these standards by completing proceeding parts of the experiment.
I note,"Scientists need to measure things accurately. What should we use to measure the height of the snowmen?" They shout, "We should use a ruler." I ask, "How do we use a ruler properly?" One child says, "We start by lining the ruler up with the snowman. We also need to make sure we start the measurement on the zero mark.
I then point out the zero mark on the ruler. Since it would be impossible to keep the snowmen exactly the same, we decide only to measure the height of the snowmen. One is a little taller than the other, so we fix it so it matches the other. Since moving the delicate snowman to a scale and back might be a risky move we didn't weigh it.
It is now time to begin the actual experiment. I show the children the Snowman Data Collection sheet. We look at each column and each row. I show them how each column represents a different snowman and each row is for each round. We measure each snowman one by one and fill in the chart under each respective snowman column titled "at the beginning."
Now we are ready for the scientific fun to begin! I fill a measuring glass with at least 8 ounces of water. I ask for a volunteer and immediately every hand shoots up.
I ask the class, "How much do water do we need? They respond, "Two ounces!"
I call on an attentive girl and ask her to fill up the small measuring glass so we have 2 ounces. She pours it in carefully and then douses Snowman 1 on top of the head with 2 tablespoons of water. We all watch as part of the snowman melts away. Another volunteer immediately measures the height and we record the data on the class chart (see photos--Snowman Investigation Photos--WATER).
Then we repeat the procedure with Snowman 2 but use 2 tablespoons of vinegar (see photos Snowman Investigation Photos VINEGAR). Of course, we don't apply a variable to Snowman 3 since it was our control but we still measure it each round. We complete 3 more rounds repeating the exact same procedure. We stop after each round, measure the height, collect the data and write it on the chart.
Then I ask the children, "Take a look at the chart. What are the results? What do the results mean? Which liquid made the snowman melt quicker? How could you tell?"
These questions help the children to develop higher level thinking skills about how to interpret results.
Next I have the students pull out their hypothesis sheets. I ask, "How well you did form your hypothesis? Did your hypothesis make sense according to your observations? Did you base your hypothesis on information you gained from the previous lesson?" These questions help them think like a scientist and help develop their reasoning skills.
I collect the hypothesis sheets to look them over. I look to see that their hypothesis is formed correctly, but more importantly I am checking to see that their hypotheses are backed up with a logical thought process by checking their completed sentence, "I think this way because...." I am looking for them to use a fact from our observations such as, "when we used vinegar is fizzed and dissolved faster." If the child's hypothesis was incorrect, (See student sample-- Scientists Form Hypotheses) but the thought process was logical, I consider their work passing. In the sample, the boy stated that water would make the mixture melt faster because in "real life" water melts snow. This is acceptable since his reasoning makes sense.
I wrap up the lesson by reviewing all the steps we took over the course of the snowmen lessons. I ask the children to think back to the previous lesson.
"What did we do to begin our investigation of snow-dough? A child answers,"We looked at it and studied it." I ask the children if they remember what it is called when scientists do that. A boy replies,"That is called observing!" We then discuss how we can observe something. One child pointed out, "Using our senses helps us observe something. We just can't taste it." We review how we tested the snow-dough by adding water and vinegar to it and watched what happened. Then I ask, "How did knowing the reaction that snow-dough had with vinegar and water help you form your hypotheses?" A child answers, "We knew that it fizzed and melted faster when we added vinegar to the snow-dough so we all thought it would melt the snowman faster." I remarked, "Great job, it sounds like all of you are thinking like a scientist!"
This experiment created a good, solid foundation for many skills that the children will encounter in our science lessons in the future. With help, the students observed an unknown substance, planned and carried out an investigation, analyzed and interpreted data and constructed explanations.