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
pre-cut 2 inch wide strips of construction paper (12×18) in the following colors – red*, pink, yellow, orange*, green, lt. blue, dk.blue, and black*
(*) be sure to have more of these colors since they are vowels
I used a paper cutter and was able to make a lot of strips very quickly ahead of time
clothes pins and string to hang up in classroom
This activity should be used after DNA and protein synthesis has been introduced. This activity will help reinforce the concept of how the sequence of DNA codons create specific amino acids, and in turn, the amino acids are joined together to create specific proteins. (link)
Each student will write the letters from their first and last name onto the student handout.
Using the chart, they will find the amino acid associated with the first letter of their first name.
For example, if the first letter is “L”, it will code for Leucine. They will select one of the codons for Leucine and write it on their chart.
Write the color of the paper link they will need for “L”, in this case, it is Red.
Repeat for every letter in their name.
Once their handout is completed, they will select the colored links, one for each letter of their name.
The colored links will be placed in the same order as the letters in their name.
On each link, write one of the codons for that letter. For example, “L” would be “CTT” on a Red link.
Loop and staple the first letter of their name.
Weave through the second letter and staple the loop closed.
Continue until all the letters have been linked together.
Hang up the protein chain, be sure to have the first letter of their name at the top.
Look for patterns – what color was used the most? Which group of amino acids was it? Which group of amino acids was used the least? Who had the longest name? Etc.
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.
Provide each lab group with an assortment of bottles
Students will arrange the bottles from lightest to heaviest by making observations
They will record the order of the bottles and their contents with #1 as the lightest and #10 the heaviest on their handout
my groups used 9 bottles, but there is room on the handout for 10
Using the set of masses, they will estimate the mass of each bottle by holding a bottle in one hand and a mass in the other hand, recording their estimations on the handout
Procedures – Part 2
Students will transfer their estimation to the back page
Using the TBB they will record the actual masses of the bottles
Then they will rank the bottles from lightest (#1) to heaviest (#10) and compare their estimation to the actual masses. How close were the estimations to the actual masses? Did they place the bottles in the correct order?
You can also use these bottles as part of your density unit, see my blog entry for more information.
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.
We are heading into Peak Hurricane Season, with forecasts predicting 12-17 named storms. Using the resources below, students can track Tropical Storms and Hurricanes, as well as learn about how hurricanes form, the parts of a hurricane, the difference between a tropical storm and a hurricane, and the intensities of hurricanes with this mini-unit from my Adopt-a-City Weather Unit (link).