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.
I used this lesson after we had already learned how to balance chemical equations using the hands on lesson I created and described below (also found on my Chemistry page):
Balancing Chemical Equations Activity – one of my long time favorite activities. Students will learn how to read formulas, count atoms, create and read chemical equations, and balance chemical equations using a hands on activity with color coded formulas:
We worked through the problems together and I called on students to first identify the chemical reaction and then balance the equation. After a few slides, they began to recognize the types of reactions quickly and had a good understanding of how to identify and balance the equations.
Cabbage Juice in an Erlenmeyer Flask with a pipette
micro-wells or small clear bathroom cups
litmus paper – blue and red
beakers and pipettes for each solution
Substances to test – diluted in water
You can have all of these set up at one station and students can pick one up and take one to their desk for testing, then return it to the station and choose another substance- you don’t have to have a complete set for each group.
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.
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.
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.