I created this mini-unit as a way to get my kindergartners really excited about science and to give them more practice participating in inquiry-based science investigations. Having kids record in their own notebooks is optional at this point. I think modeling how to record on chart paper and leaving the journals tucked away is a very good idea. I think the value of this unit is in practicing those key skills: asking questions, developing a plan, making predictions and analyzing evidence/making claims.
One more thing--although it has a "rainbow" theme, it is not actually about rainbows. (We learn about rainbows later in the year during our weather unit).
Day 1: Mixing Colors
This is a very simple activity that involves mixing colored water to create new colors.
I start by posing a problem: Yesterday, I painted a rainbow. I really like my rainbow, but it's not very colorful because I only have 3 colors of paint--red, yellow and blue. I wish I had more colors so that I could make a really pretty rainbow.
That should activate the children's prior knowledge (schema) on colors. I bet many of them already have experience mixing colors. I write what they already know on chart paper and then we work together to generate a list of questions about colors. Then we choose a focus question. I already know that I want the focus question to be something like "How can we mix red, yellow and blue to make new colors?" So I manipulate guide them to that question.
Now, we make a plan to investigate this question. Again--I know that I want the kids to mix colored water together to make new colors. I tell the kids that I don't have very much paint and want to save it to make a new rainbow. But I have plenty of water and food coloring. I "guide" them into coming up with the "correct" plan!
Because I want the kids to be independent, I put them in charge of most of the prep work. But they are, after all, still 5 years old--so I use the Super Scientist Procedure to guide them. For example: Scientist #1, please fill up 3 cups with water. Scientist #2, please squeeze 5 drops of red food coloring into one cup of water. And so on. You will find the procedure that works best in your class. Yes, there will be spills! But it's only water! (Wait 'til we get the really messy stuff out!)
Basically, for each table, you want a cup of red water, a cup of blue water, a cup of yellow water and at least 3 empty cups.
At this point, stop and have the kids make predictions about what will happen when the colors are mixed, and record them on the chart paper. You can also have them record their predictions in their own science journals.
Now direct the students to mix the colors and observe the results. For example--Scientist #3, please pour some yellow water in an empty cup. Then pour a little blue water in the same cup. Stop and talk about the results and whether or not their predictions were correct. Record the results on chart paper and/or in the science notebooks. Repeat for all 3 secondary colors.
When all the data, or evidence, has been collected, work with the kids to make "claims"--i.e. "We claim that red and yellow make orange because when we mixed the red and yellow water, it turned orange."
Now the kids are probably full of new questions--the most obvious being "What will happen when we mix all the colors together?" (You know you have to let them try it, right?) Record their new questions on the chart paper and either give them some time to investigate now or save for later investigation/research.
Day 2: Now Try Paint!
We start by reflecting on yesterday's investigation. Then I pose a new problem:
So, we know that mixing red, yellow and blue water will make green, orange and purple water. But I tried painting a rainbow with the water, and it did NOT work!
So now, guide the kids to come up with the question:
What will happen if you mix yellow, red and blue paint?
Time for the plan. I already know I want them to mix the colors in a zippered bag, but I want them to think it was all their idea (is that cheating?) So, I guide them by showing them the paint and baggies and tell them that I don't have a lot of paper (I am such a liar!) and so on until we have resolved to put a little squirt each of red, yellow and blue paint in a bag and zip it up.
Note: I am all for independence, but I'm also not stupid! I squirt the paint in and double check that the bag is sealed before I let them smush!
We talk about the best plan for mixing the paint--should they squish it all together at once, or should they mix little areas one at at time so that they can clearly see the results?
Before I let them squish, we make predictions about what will happen and record them on chart paper and/or in our science notebooks.
Then squish, observe, record data on chart paper and/or in science notebooks, make claims ("We claim that blue and yellow make green paint because when we mixed them, they made green paint"), reflect, ask new questions...you get the drill!
Day 3: Painting a Rainbow
Today I give each kid a plate with a squirt of red, yellow and blue paint and let them mix colors and paint their own "colorful" rainbows. I even give them a squirt of white and black paint and let them experiment.
Rather than doing a whole formal lesson, I just walk around the room and talk to the kids as they work--having them tell me their "plans" and make predictions and claims. I use that language, because I want them to become competent at using it. After they have dried, we glue the rainbows in their science notebooks. (By the way--because this activity is not actually about the science of "rainbows," I do not worry about ROY G. BIV. I just want them to experiment mixing the colors).
Day 4: What About Markers?
Today, I have the kids do a chromatography experiment. If you've never done this, it's a lot of fun! Here is a website that has a simple procedure for completing this activity. I have the kids work in table groups and use the Super Scientist routine to manage them.
Basically--you color some marker on the end of a paper towel about 1 inch up (I cut my paper towels in half and do 3 colors on each). Then you stick it in a glass with about an inch of salt water. The water will travel up the paper towel, and as it does, it will carry the ink with it. But some colors in the ink travel further up the paper towel than others, thus "separating." You have to look closely, but you can see the red and yellow in the orange, etc.
Problem: I start by having the kids reflect on what they've already learned about mixing colors. Then I show them a green marker, and ask how they think it is made. I let them tell me what they know, and then ask their questions, recording it all on chart paper.
Question: I guide the kids into developing the following focus question: Is a (green; orange; purple) marker made from (blue, yellow; red, yellow; blue, red)?
Plan:Obviously, most 5 year-olds will not have a lot of experience with chromatography and will not know how to separate out ink colors. So I show them by separating out the colors in a black marker (It separates into several colors!). Then I have them develop a plan for separating out the colors in the green, orange and purple markers. (You might want to experiment on your own before this lesson. Some markers work better than others. I used plain Crayola (not washable) but have had success with others, also)
Prediction: Have the kids predict what will happen when you do the experiment with the orange, green and purple markers.
After you have finished with the experiment, record the results on chart paper and/or in the science notebooks. Reflect on the results and ask new questions for further investigation/research.
A fun extension is to have the kids predict what, if anything, will happen to the red, yellow and blue ink.
Day 5: Open
I'm going to leave this last day open so that we can possibly explore other questions the kids come up with. If they don't have any other questions, we'll mix colored play-doh or something! I might also read some books about colors (which I don't want to do before the kids have had a chance to explore).