I updated my Dunkin’ for DensityLesson for 2016, I use this lesson with my 6th graders as part of our unit on properties of matter. I wanted it to be more data driven and have them analyze the data from all of their trials, and then compare their data to their classmates. I changed the objective to:
Change the density of the film canister so that 90-99% of the canister is suspending under water.
This post highlights the eight Scientific and Engineering Practices and spotlights a few lessons related to each practice. I had this as eight separate posts but decided to consolidate for easier viewing.
For more details and examples about the Science and Engineering Practices, visit NSTA.
Tag: SEP8 – click for more lessons that cover this practice
This is one of my favorite activities from our minerals and mining unit. It takes about 1 whole class period to explain the activity, collect data, eat the cookie (& crumbs), and clean up. We discuss our results the next class and determine who made the most profit.
When determining the value of the chocolate ore, I have the students place their chocolate pieces close together in one area of the map. When they are done, I go around and circle the area of chocolate and give their chocolate a rating. They count the number of boxes their chocolate covers and enter it into their spreadsheet.
If there are crumbs attached to the chocolate, I call that ‘slag’ and it lowers the value of the chocolate ore. This leads to a great discussion afterwards when we compare the profits and talk about land use. Is it better to get out as much chocolate as you can, even if you get a lot of slag, or is it better to remove just the chocolate even though you will have less in the end? How is this similar to coal mining? Diamond mining?
Erlenmeyer flasks filled with red, yellow, and blue solutions of food coloring and water
5 drops of food coloring per 200 mL (25 per 1L)
3 x 25 mL Graduated Cylinders
3 x 10 mL Graduated Cylinders
beaker filled with clean water
large beaker for used water
this activity took 2x 50 minute class periods
This lab is an updated version of the classic Rainbow Lab (link) that has been around since the 80’s (Measuring Liquid Volume with a Graduated Cylinder 1988). I used this for many years with my 5th graders, and previously with my 6th graders in the early 2000’s. Now that I am teaching 6th grade again, I wanted to make it more open ended and challenging. The purpose of the original version of the lab was twofold: First – could they follow directions carefully to make a rainbow? Second – how precisely can they measure liquid volume?
For the new version of this lab, I created new objectives and assessed the students based on their problem solving, collaboration, and measuring skills.
Students will be able to precisely measure liquids with a graduated cylinder
Students will be able to create their own lab procedures using the given parameters to guide them
Students will create new mixtures and solutions
Students will be able to record accurate data
Students will collaborate and problem solve to achieve a common goal
Students will test, evaluate, and select the best proportions to create the colors orange, green, and purple
each group made 3-4 different combinations for each color and had to, as a group, determine which combinations of primary colors created the best secondary colors
Students will follow proper lab procedures to avoid color contamination
Students will record and analyze data from the whole grade and compare their findings to the averages from each group, what patterns or trends did they notice in the data?
Students will create their own ‘designer’ color and share it with the class
this was fun way to wrap up the activity, we had a ‘fashion’ show with each group coming up to the front of the room to showcase their newly created and named colors
if time allowed, at the end we made a rainbow with each student holding their test tube and standing next to a person who had a color similar to their own, from Red to Purple
This sugar density activity is one I have never tried before, I actually ‘borrowed’ the idea from my son’s HS Chemistry Teacher. He came home and told me they made different colored layers using only sugar, food coloring, and water. I immediately jumped on the computer and thought about how to use this in my 6th grade classes, we are in the middle of our density unit and it would be a perfect opportunity to try it out.
One of my goals for this year is re-examine my lessons and see which activities I can make more open-ended when appropriate. For this activity, most of the resources I found told the students exactly how much sugar to put in each layer and what order to place the colors into the test tube or some other type of container. I didn’t want my students to follow step by step procedures, but wanted it to be more of an exploration type of activity. I had no idea how this would turn out but gave it shot anyway.
I gave them the problem, the parameters, the tools to complete the activity, and sent them on their way. It was great to see them figure out how to solve the problem, talk out strategies, and to see them go through the trial and error process. Each group came up with a different way to solve the problem and some groups struggled more than others. I met with each group to facilitate, ask questions, and had them explain to me what they were doing and why. Overall, it was a successful lesson, they enjoyed the activity, and it really solidified their understanding of density.
I am also incorporating more open ended writing in science and I enjoyed reading their reflections about the activity.
This was the easiest, and most inexpensive way to make cartesian divers I have ever tried, and each student got to take theirs home after class. Did I mention how much fun it was?!
semi-transparent to transparent bendy straws – 1 per student
colored paper clips – 4-6 per student
scissors – 1 per 2-4 students
2L bottle with cap – 1 per 2 students
beaker of water – 1 per 2-4 students
tray to contain spills -1 per 2 students
optional: eye dropper with blue colored water
Part 1 – Demonstration:
As part of our density unit, we talk about the concept of buoyancy – why do objects float or sink? Using a 2L bottle of water, a glass medicine dropper, and some blue food coloring, we made guesses and observations about the cartesian diver.
The medicine dropper is filled with blue water, checked for buoyancy, and then added to a 2L bottle. Students gather to make observations. What do you think will happen when I squeeze the bottle? What will the blue water do? Why did it sink? Why did it float? What is happening to the air in the diver? What is the water doing? Did the mass of the diver change? The density? Students share their ideas and we come to a conclusion as to why the diver floats and sinks.
Part 2 – Build and Explore:
After the demonstrations, students get to build their own divers and explore on their own. Some tips to keep in mind:
Be careful bending the straw, any cracks will make the the straw useless.
After bending the straw, cut off the excess length of straw so that both side are equal in length. (You can save the rest of the straw for future activities)
Attach one paper clip as shown in the diagram below. Additional paper clips can be easily added or removed by sliding them on or off the main paper clip. (Like keys on a keychain)
Use a rescue hook for any divers that do not float back to the top.
Remind students to place the cap back on the bottle TIGHTLY – or water will shoot out of the bottle when they squeeze it.
Lunch or serving trays work nicely to contain spills.
This is a wonderful problem solving and hands-on activity to use as part of your density unit. The students enjoy the challenge and have a solid understanding of density after completing this activity. Even though students quickly figure out how to make the canister float and sink, making the canister suspend is pretty challenging and requires a lot of trial and error and problem solving.
To qualify as suspending, the film canister needs to float just under the surface of the water, with a small portion of the top just breaking through. How I also verify that it is suspending is by pushing the film canister to the bottom of the tank, if it comes up very slowly to the surface, it counts – if it comes up quickly or stays towards the bottom, it doesn’t count. Students then need to figure out that if it comes up too quickly, they need to add to the mass, if it comes up too slowly, they need to remove some of the mass. It will take several tries to get it just right.
one canister per 2 people works well, they can reuse the canisters if you don’t have enough to give each set of lab partners 3 canisters
if they reuse the canisters, be sure that they find the mass before they empty the contents
An assortment of small objects such as pennies, paper clips, stoppers, small pebbles, etc…
Introduce the Dunkin’ for Density Challenge – their goal is to make the film canister float, suspend, and sink by placing contents inside of the film canister.
Many students will say that the canister will float with nothing in it, but they must place a few objects in it for it to count 😉
On a side note, a mini history lesson on film and cameras is fun to discuss since most students have never used a camera that used film
Explain the procedures, review how to use the TBB, note that the film canister must seal completely and be air tight so that water doesn’t enter, and also demonstrate how to use the dunk tank properly and to dry off the canister before finding the mass.
Do not give the students the value for the volume of the film canisters until they have collected their data. If the students know the volume of the film canister, they may figure out the mass needed to make the film canister’s density close to 1.0 g/cm3.
The value is approximately 39 mL or 39 g/cm3 – verify with a large graduated cylinder that the film canister can fit inside of – or use an overflow can to find the volume (link).
I will give the volume to each set of lab partners individually and ask that they don’t share that information with the class.
Once students have calculated the density, collect class data on a spreadsheet projected on the board/screen.
Discuss results – why did the film canister float, suspend, or sink in the tank of water? What relationships did you notice?
For more lessons related to the Properties of Matter, click here (link)
For my posts, I am tagging the Science and Engineering Practices (SEP) that I think best fit the lessons on my blog. To find lessons related to each practice, you can use the search box to find them or click on the tags on each post to find similar lessons: