Dunkin’ 4 Density Activity

We completed the “Dunkin’ for Density” activity today, collected our data, entered it into excel, and discussed our findings. 

For this lesson, the kids had to make 1 film canister float, 1 film canister suspend, and 1 film canister sink in water by changing their densities.  We used white/clear plastic film canisters and I calculated the volume as 39 ml or cm3 by using water displacement and a large graduated cylinder.  (The film canisters hold about 35 mL of water, in case you were wondering!)

Supplies: plastic tray, 3 film canisters per set of two lab partners, a bowl or large beaker filled with water, pennies, rubber stoppers, cork stoppers, paper clips, and bits of clay. I also had a really large/deep bowl as the “official suspend testing tank”.  Once the kids tested their suspending canister, they brought it over to be officially checked by me.

Using whatever combination they like, they place the items into the film canisters to complete the task. I only have two rules: you must have at least one item in the canister (which I forgot to tell the 1st class!) and it must be able to close and seal tightly so no water enters the film canister. The floaters and sinkers are the easiest to do and the kids figure those out pretty quickly. But I am very picky about my definition of suspend and it drives them nutty!  In order to qualify as a suspender, the film canister has to touch the bottom of the bowl when I tap it, and then float up slowly until it is near the surface of the water. Only a small part, if any, may rise above the water line. This is a great problem solving activity and after a few tries, they usually get just the right combination of stuff inside their film canisters to make the density very close to 1 g/cm3. (For this to happen, the mass ends up being close to 39 g,)

Once they have completed all three tasks, they use the TBB to find and record the mass into their notebooks. (Tip – make sure the film canisters are dry before they use the TBB) (Tip #2 – have them find the mass of an empty film cansiter before they begin dunking.)  Using the formula for density (D=m/v), they find and record those densities into their notebooks.  Once everyone is done, each group reports their data and we enter it into the excel spreadsheet, displaying the data on the SmartBoard. We then discuss the data and I ask the kids if they notice any patterns in the data. (Sometimes I’ll show the data from previous classes so they can compare their results to older experiments.)

After we have discussed the data, they answer the analysis questions and write a conclusion on page 41, the right side of their notebook. The one misconception that some kids may have is that the film canisters sank because they became heavier.   We talk about how yes, they did get heavier, but they sank because they became denser.

Notebook:

pg. 40 – Dunkin’ for Density

pg. 41 – Analysis: Dunkin’ for Density

Excel Spread Sheet Template to enter data  (This is a very old template, it won’t graph for some reason. If I can, I will update it.)

 

If you have completed this activity, I would love to hear from you and see your results!

Density Bottles

As an introduction to density, I do a demonstration/discussion/group activity using density bottles. They are small sports drink bottles that I estimated to have a volume of approximately 400 mL.  There are 5 bottles, each  filled with a different item: cotton, air, sand, rice, and colored water.

These are some of the questions I used for our discussion:

• “Do these bottles have the same volume?” There is some uncertainty at first, but then they quickly say “yes”.
• “Do these bottles have the same mass?” No
• “Why don’t they have the same masses?” Variety of answers
• “Which one do you think is the heaviest?” We do a survey with a show of hands then have the kids give some reasons for their answers
• “Which one do you think has the most ‘stuff’ crammed into the bottle?” It’s interesting, there is a wide variety of answers and it usually doesn’t match the answer to the question of which is the heaviest

I tell them that they will find out the answers in a minute! We watch the BrainPOP movie for Measuring Matter. After the movie, I give the analogy of standing and waiting for an elevator.  Two identical elevators open up: one has 2 people in it and the other has 15 people in it.  “Which elevator would you choose and why?” Naturally, they say the one with only two people, there is more room in that one. I ask them, which elevator is denser? The one with 15 people, of course. We then discuss that there is less empty space available in the elevator with 15 people in it.  I then relate molecules to the people in the elevator, matter that has a lot of molecules, or atoms, crammed into a given space are denser than objects whose molecules or atoms have a lot of empty space between them.

I hand one bottle to each group and have them find the mass.  We collect the data and I write it on the board. I re-ask the following questions:

• Which one is the heaviest?
• Which one has the most ‘stuff’ crammed into the bottle? (Variety of responses)
• Which one is the densest? (Variety of responses)

Now that we have the mass and the volume, we calculate the densities for each bottle.  After we collect the data, I have the kids come over to the dunk tank.  One at a time, we predict which bottles will float. We do a survey and raise our hands if we think the bottle will float.  I have one student place the bottle into the tank and we see if it floats or not. We continue until all 5 are in the tank.

The cotton, rice, water, and air filled bottles floated, the bottle with the sand, sank to the bottom. I then ask the kids “Why did the bottle of sand sink?” They usually say it was the heaviest. I then say, “But a cruise ship is a lot heavier, and it doesn’t sink? Why?”  I give them a hint, “Look at our data, what do the bottles that floated have in common?” After a while, they figure out that the bottles that floated, all had numbers that were decimals, or less than one.  The sand was over 1, and sank. I tell them the density of water is 1, so objects with a density greater than 1 will sink.

We talked about how the bottle of sand is the densest b/c it has the most amount of “stuff” crammed into the same space, and that there is less empty space between the atoms.  I tell them that the density of gold is 19.3 g/cm3, and that if this bottle was filled with gold, it would be about 19 times denser, meaning that there would be 19 times more “stuff” crammed into the same space. The next day we talked about the story of Archimedes.  We calculated how much mass the same bottle would have if it was filled with pure gold - it would be 7,720 grams!! 

After the dunk tank, we did a small group acitivty using the graphic organizer from BrainPOP.  It shows a ring, balloon, yo-yo, and pillow.  We have to categorize them according to mass, volume, and density, from highest to lowest.  We do one category at a time and I give them a minute  for each, going over the answers between each category. I liked this graphic organizer b/c it really made them think about each item and their properties.

pg. 34 - BrainPOP – Archimedes

pg. 35 - BrainPOP – Mass, Volume, Density Graphic Organzier

Triple Beam Balance Activities

To introduce the triple beam balance (tbb), I had the students complete a tbb tutorial where they learned how to find the mass by reading the riders on the 100′s, 10′s, and 1′s beams and how to combine those values into a single value. 

My expectations were for them to read the mass to the nearest 10th, but if they wanted to guess the 100ths place, they could attempt that as well.  The students caught on very quickly and some were really proud of themselves if they guessed the 100ths place exactly.  In the past, when I introduced the tbb and didn’t use the tutorial, most students had trouble reading the ones beam and the 10ths place value.  Completing the tbb tutorial really increased the students’ accuracy in reading the measurements on the beams and very few, if any students, asked for help when they used a real tbb and had to record the masses.

Another thing I really like about this tutorial, is that the students have immediate feedback as to if their answer was correct or not.  If their answers were incorrect, they could compare their answer to the correct answer and reflect about it, figure out what they did differently, and how they can correct it for the next problem. 

After completing the tbb tutorial, I introduced the real tbb with a demonstration on how to use it correctly and how to  find the mass of an unknown object.  I also emphasized that the riders have to click into the notches for the 100s or 10s beam, otherwise its not that exact value, its somewhere in between two adjacent values. We also discussed the proper way to hold, carry, and take care of a tbb.  When the tbb is not in use, my mantra is “Riders to Right“.  Moving the riders to the right reduces the bouncing of the beams when they are being transported or not in use.

Each lab table had a group of random items from the science room and they had to find the masses of whatever they liked, and however they wanted to group the items. For example, the could stack 3 blocks onto the pan and find the combined mass of those items.  They could do a single item such as a penny, too.

Notebook handouts

pg. 30 – Reading a Triple Beam Balance – Laptop Activity Link

pg. 31 – Vocab: TBB Balance

pg. 32 – TBB Mass Lab

pg. 33 - TBB Analysis – Answer questions #1-5 and write a conclusion

Current Events Blog

Each year, I usually do some type of current event assignment with my students.  This year, to promote science literacy and 21st century skills, I thought I would try having the kids blog for their current events. I created a free edublog account and came up with a format that I thought would be appropriate for 5th graders, most of which are 10 years old.

Two of the concerns I had last year with kids finding their own articles were:

• choosing appropriate news articles from reliable sources
• articles that were at their reading level

For the blog, I came up with a format where I would post articles from various reliable sources that cover a wide variety of topics.  The students could then pick any article that they were interested in and write a summary and reflection.  I posted some questions to give them an idea of what they would be learning about when they read the article.  The second thing that I liked about this format was that the kids could then read comments from other students who read the same article they did.

Once the students are comfortable with using the blog and reading news from reliable sources, I will ask them to send me articles that they are interested in and I can post those articles on the blog.  To help students find good news articles, I set up a pageflakes page which posts RSS feeds from all the science news sites I have bookmarked.  It acts like a funnel, funneling all the information into one page instead of going to all the different news websites.  Its very easy to see all the current headlines and click on something that you are interested in reading about.

When the students are writing their summary and reflection, I have them type it into Word, proofread, spellcheck, and edit first.  I also tell them to save a copy on their computer.  The problem with typing directly into the comment box is that they can not spell check or edit their work as easily.  And if the webpage or internet connection snarls up, they lose everything that they worked on. When they are ready to post, they copy and paste those two paragraphs into the comment box under the correct article.

For their summary, I ask that they have at least 2 sentences that answers the questions: who, what , where, when, and why.  Their reflection is more about what they learned, their opinions, thoughts, etc… And that should be at least 3-4 sentences.

When a students submits a comment, it gets held for moderation.  In the blogging dashboard, a little orange square pops up next to the comments tab and tells me how many comments I have waiting to be moderated.  I click on it and can see the new posts.  I  approve the posts and they are instantly published on the website.  I can edit the comments, but I choose not to. The only thing I will edit is if the kids accidently post their last name, otherwise I leave it as is.  The main reason I moderate the comments is so that only my students are the ones posting to the blog, not anyone else since it is open to the public.

I came up with a simple rubric to grade the postings. They complete one current event assignment every 6 day cycle.

Do you use blogging in your science class? If so, would love to hear about or see your class blog.

Volume Labs- Regular and Irregular

Over the period of about 3 days, we covered finding the volume of a rectangular prism using the formula length x width x height and finding the volume of irregularly shaped objects using water displacement.  I usually do these labs as stations labs, but decided to have the kids do the activities at their tables.

For finding the volume of rectangular prisms, I placed some everyday objects onto a tray as well as some scrap wood from our woodworking shop. Students could choose what they wanted to measure in whichever order they like.  We then compared our results.  I usually allow a  +/- 2 mm window for their measurements.

I made up some hand signals and we practiced them as a class so that the students could remember the three dimensions when taking their measurements.  It helped a lot and I saw the kids use it to orientate themselves for the 3 dimensions.

• hold your hand flat and straight on the table = length
• hold your hand sideways with your wrist bent at a 90 degree angle = width
• hold your hand straight up in front of you, fingers towards the ceiling, with your wrist at a 90 degree angle = height

What happens sometimes is that they forget which side they already measured or have trouble choosing which side will be their length, which side is their width, and which is the height. I have them lay the object flat on the table in front of them and have the longest side be their length and pointing towards them to get them started.

For the irregular volume, I kept it simple and the kids really liked it.  I placed an assortment of rubber stoppers and marbles on their try.  Some stoppers were solid, some had one hole, some had 2 holes, some were skinny, some were wider. They could place whatever combination they wanted into the graduated cylinder and they recorded what they tried. They also asked questions like “Does the stopper with 2 holes have a smaller volume than a stopper with no holes if they are the same size?” and they tried it out.

They also figured out that if they fill up the graduated cylinder with too many stoppers, they couldn’t find the volume b/c it was more than 100 mL or items were no longer in the water, they were stacked above the water line.

The spoon is there to prevent the items from falling into the beaker, they cover the top of the graduated cylinder, drain the water, and then place the objects back on the try.  Keeps everyone dry!

See below for my notebook pages:

pg. 20 – Volume Lab: Pre-Lab,  Length, Width, & Height

pg. 21 – Practice: Measuring in cm & mm

pg. 22 – Irregular Volume Lab: Pre-Lab,Water Displacement

pg. 23 – Practice: Reading a graduated cylinder, water displacement, volume (page 1)

pg. 24 – Practice Reading a Ruler pg 1

pg. 25 – Practice Using a Ruler cm #1-10, mm #1-10

pg. 26 – Practice using the formula L x W x H  pg.1

pg. 27 – Practice: Reading a graduated cylinder, water displacement, volume (page 2)

Quiz/Test Screens

In my classes I have anywhere from 2 to 4 people at a lab table.  So when we have quizzes or tests, I use privacy screens to help keep eyes from wandering.   First, I take 2 manilla folders and overlap one side of each.  I then add 2 staples to the top and 2 staples to the bottom.  Second, I cut it in half, then staple the new tops and bottoms.  This creates a 3 sided screen that is about 15 cm tall (6 inches).  Its tall enough to cover the papers but low enough where I can still see the kids and their papers.

For short quizzes, I may place a puzzle on the back or let them doodle until everyone is done.  For tests, I let them have 2-3 challenge puzzles handy so when they are done before anyone else they can work on those quietly at their desk for challenge points.  Challenge points are used to earn prizes like pencils, erasers, 1-day extra hw pass, etc…

Drops of Water on a Penny Lab

Last week we completed the Drops of Water on a Penny Lab.  In this lab, we learned about surface tension, how to use a pipette, how to collect data, how to use a stem and leaf plot, how to do an experiment, and what variables are.  Our question was: Does soapy water make a difference?

Each set of lab partners completed 3 trials each for clean water and soapy water, then calculated an average for each.  We posted our averages onto the stem and leaf plot. What I like about the stem and leaf plot is that it allows you see how the numbers are grouped- it’s a visual representation that allows you to see patterns and ranges quickly.

One of the things we talked about was that if we all completed the same experiment, why didn’t we all get the same results?  Some ideas were that some people used smaller or bigger drops of water, some held  the pipette really close to the penny while some held the pipette higher above the penny. Some pennies were newer and smoother while others were older and rougher. One other idea is that some cups of soapy water were soapier than others.

So, did soapy water make a difference? Did soap affect the surface tension of the water? What do you think?

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