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.
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
For this activity, I used the set of density blocks from Flinn Scientific. Each group of students had 6 blocks made of the same material. Their challenge was to identify the material using their measurement skills to calculate the mass, volume, and density of each block. This activity also reinforced the concept that the density of an object is constant.
Demo & Discussion – For this part of the lesson, students will not handle the bottles, they will answer discussion questions based on their observations only.
Share observations about the bottles.
What do the bottles have in common?
What is different about the bottles?
What do you think the original contents of the bottle were?
What phases of matter are shown?
Are any of these bottles empty? Explain.
Do all of these bottles have air in them?
Which bottle has more air in it: Cotton Balls or Water? Explain.
Which bottle is filled the most? Least?
Which bottle has has the most ‘stuff’ in it? Least?
Which bottle is the heaviest? Lightest?
How would you order these bottles from lightest to heaviest?
Estimate the mass of each bottle in grams.
Which bottle is the densest?
How would you arrange these bottles from least to most dense?
Which of these bottles can have more of the same ‘stuff’ added to the inside of the bottle? Explain.
Which bottle(s) would float in a tank of water? (I do this at the very end of the lesson with everyone at the sink)
Hands On Exploration
Each group will have one set of bottles or take turns using the demo bottles and sharing their findings.
Using a triple beam balance, the volume of the bottles, and a tank of water, answer as many of the questions above as you can. (for our calculations, we use the volume of the bottle’s original content (500 mL of sport drink) to give us an approximate density, not the actual density – for comparison purposes only)
How did your findings compare to your observations and predictions?
Dunk tank – time to find out which one will float!
Give each group of students a new set of bottles (ones that they have brought in from home) and have them make observations, predictions, and density calculations.
Additional Bottle Ideas:
laundry detergent – liquid or powder
different shapes of pasta
pop corn kernels or popped
Have each student bring in a bottle from home filled with the contents of their choice so that you have enough bottle to compare. Match similar bottle shapes/sizes together for each group or match similar contents in different sized bottles for comparison.
You can also use these bottles as part of a Triple Beam Balance Activity (blog entry).
I use these blocks as part of a density lesson as well
Prior to this set, I used blocks of scrap wood that were cut in the wood shop, but any rectangular shape works well such as chalk boxes, expo boxes, staple boxes, tissue boxes, playing cards box, dice, etc…
Prior to having the students record the measurements for the blocks, we go over the importance of how to orient the blocks before measuring. A problem that students often run into is that they end up measuring one of the sides two times, and not measuring all three of the sides. Even though the right-hand rule is not used for volume, it helps to find the L, W, & H of each block.
In the image below, Z = Length, Y= Width, and X = Height. Mathematically, it doesn’t matter which side is designated as the width, height, or length since all three sides are multiplied, but this will help students measure all three sides properly. Students should place the block in their hand and align their fingers with the three sides of the block. Once they have decided on how to orientate the block, they can record their measurements.
For this lab, you can have several stations set up around the room with 1-3 blocks at each station. I assign each block a number and using a black sharpie, write it right on to the block itself. Not all blocks have to be measured, once each student has measured 10-15 blocks, they can go back to their seats and compare their measurements with a partner. We go over the answers together as a class once everyone is done.
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)
“Pour to Score” is an interactive website created by PBS. The objective of the game is to pour the water between the larger container and the smaller container to create 8 different volumes of water.
At first glance, it may seem like an easy exercise in addition and subtraction, but it requires problem solving skills, logic, and patience. My 5th graders have enjoyed using this game as part of our volume unit. Some students will figure out the pattern quickly, and advance to the next few levels, while for others, it will require trial and error, and perseverance.
Above is a photo of a 4-door foldable for the three density related formulas: D= M/V, V= M/D, and M = VxD. The 4th door has step by step instructions on how to solve a word problem. Along with the formulas, inside the foldable are 3 practice problems, and a few notes about mass, volume, and density.
On the right side of the notebook are practice problems. Students have to determine which formula is needed, set up the problem, solve, and add the correct units. They can refer to their foldable for the formula and how to solve the problems. I have the students close the flaps for the known values. For example, if the problem states the Density and Volume values, they close those doors on the foldable leaving the Mass flap open, since it is the missing value. That is formula they will then use to set up the problem correctly and solve.
My main goal for this lesson is having the students choose the right formula, set up the formula by plugging in the known values (this is a step that the kids don’t feel the need to do/show as part of their work), and adding the correct units when done. Some students may have a little difficulty with multiplying or dividing decimals and rounding to the 100ths place, so I usually go over that before we begin by modeling a few problems with them.