Triple Beam Balance – Bottles of Stuff!



  • Single Serving Size (1L or less) bottles filled with various items
    • students brought in materials of their choice over the course of a week
  • Triple Beam Balance (TBB)
  • Mass Set
  • Student Handout (Triple Beam Balance Bottles pdf)


Procedures – Part 1

  1. Provide each lab group with an assortment of bottles
  2. Students will arrange the bottles from lightest to heaviest by making observations
  3. 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
  4. 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

  1. Students will transfer their estimation to the back page
  2. Using the TBB they will record the actual masses of the bottles
  3. 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.

CK-12 Online Textbook

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Our 7th grade science teachers, including me, are testing out the CK-12 online textbook and resources this year. We have a 1-1, 24/7, laptop program where 7th and 8th graders have school issued laptops and can bring them home at night and on the weekends.

You can create your own textbook from scratch by making selections from the thousands of resources, or use the one they have as a guide and pick and choose what you would like the students to access.

You can create your own group, invite students join, assign reading or quiz assignments, and check on their progress.

Has anyone else tried CK-12? If so, would love to hear your thoughts on it.

Here is the life science Flex-Book: 

First 2 weeks of school

These first 2 weeks flew by! What we covered in class so far:

  • Day 1 & 2 – Introductions, Scavenger Hunt (blog link), & prep for our YMCA trip
  • Days 3-4 – YMCA overnight trip
  • Day 5 – Cup Stacking Challenge (blog link)
    • This was the first time I tried this activity, and I was really happy with how well it worked in the classroom. Students were engaged and worked as a team to complete each challenge. Due to time, most groups did not complete all 6 of the tasks, but that wasn’t my goal. Collaboration, Communication, and Perseverance were my objectives.
  • Day 6 – Nature of Science (Tangrams Activity) (link) & Intro to “I am a scientist” (blog link)
    • This was the first time I used this activity and it lead to a nice discussion about learning new things, being challenged, and persevering and how somethings seem really hard at first, but then once you master it, it becomes easier.
  • Day 7 – I am a scientist & Instagram (blog link)
    • I am in the process of collecting the Instagrams that the kids drew and they came out great! I will post some examples next week.
  • Day 8 – SpongeBob safety scenarios (blog link)
    • This was an updated version of an activity that I have done each year, and it was much more engaging for the students, they enjoyed the challenge of finding the broken rules. This also reinforced their reading comprehension, being able to use clues from the text, evaluating text, summarizing the safety rules into 2-3 words only, to name a few.

Some pictures from my 6th grade classroom:

Working as a team to complete a task
Working as a team to complete a task
Cup Stacking Challenge – Challenge #4
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Cup Stacking Challenge – trying to pick up a cup that fell over without using your hands
Tangram Challenge – How can we fit in the extra piece?
SpongeBob Safety Scenarios – finding the safety violations, identifying the rules, and summarizing them into 2-3 words – can you find all of them?

Density Bottles Demo

Density Bottles
Density Bottles: Sand, Air, Rice, Water, & Cotton Balls in 500 mL bottles

How to use density bottles:

Demo & Discussion – For this part of the lesson, students will not handle the bottles, they will answer discussion questions based on their observations only.

  1. Share observations about the bottles.
  2. What do the bottles have in common?
  3. What is different about the bottles?
  4. What do you think the original contents of the bottle were?
  5. What phases of matter are shown?
  6. Are any of these bottles empty? Explain.
  7. Do all of these bottles have air in them?
  8. Which bottle has more air in it: Cotton Balls or Water? Explain.
  9. Which bottle is filled the most? Least?
  10. Which bottle has has the most ‘stuff’ in it? Least?
  11. Which bottle is the heaviest? Lightest?
  12. How would you order these bottles from lightest to heaviest?
  13. Estimate the mass of each bottle in grams.
  14. Which bottle is the densest?
  15. How would you arrange these bottles from least to most dense?
  16. Which of these bottles can have more of the same ‘stuff’ added to the inside of the bottle? Explain.
  17. 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

  1. Each group will have one set of bottles or take turns using the demo bottles and sharing their findings.
  2. 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)
  3. How did your findings compare to your observations and predictions?
  4. Dunk tank – time to find out which one will float!

Further Exploration

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:

  • Rocks/pebbles
  • laundry detergent – liquid or powder
  • paper clips
  • paper shreds
  • crayons
  • marbles
  • flour
  • bread crumbs
  • coffee beans
  • beans
  • different shapes of pasta
  • pom-poms
  • pop corn kernels or popped
  • Lego pieces
  • salt
  • dish-soap
  • beads
  • yarn/string
  • etc…

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).

Reading a Graduated Cylinder- Free Online Resources

Image Source: Biochemies

(For lessons and resources on finding volume using water displacement, please see my earlier blog entry)


  • The graduated cylinder has markings, like a ruler, to measure volume for water and other liquids
  • I like to use food coloring and water for the students to practice their measurements, it makes it easier for them to read the values, plus it adds some pizzazz to the lab.
    • I mostly use either blue or green food coloring, the red can stain, yellow is not dark enough.
  • Place all materials on a lunch tray for each group to contain spills and make for a very easy clean up.
  • Glass graduated cylinders can break if knocked over, plastic is more durable but can be harder to read.
  • Have students explore how to use read and use graduated cylinders:
    • Students can explore handling and pouring water into the graduated cylinders and reading the values.
    • Once they have mastered pouring and reading, they can practice measuring specific volumes such as 10 mL, 20 mL, 42 mL, 58 mL, etc into the graduated cylinder.
    • You can also set up stations with pre-measured graduated cylinders and have them practice reading the volumes.
      • Have cylinders of different sizes and increments to make it more challenging.
      • You can place task cards/answer keys at each station so students can self check once they have made their readings for immediate feedback.


  1. Reading Graduated Cylinders – (FREE) A nice power point presentation from Teachers Pay Teachers to introduce students to reading graduated cylinders (link)
  2. How to Read Liquid Volume video (link)
  3. Super Teachers Worksheet – practice problems (pdf)
  4. Measuring Liquid Volume – practice problems (pdf) (No answer key)
  5. Science Starters/Warm Ups/Do Nows: (Graduated Cylinder ppt), (Beaker/Erlenmeyer ppt)
Image Source: CK12

Finding Volume of Rectangular Prisms Using Length x Width x Height



  • Handout – Volume Lab (pdf)
    • This handout includes a pre-lab assessment and answer key
  • Rulers
  • Calculators
  • Blocks (set from Flinn)
    • 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.

Image Source:

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.

Additional Resources:

  1. Reading a metric ruler practice worksheet (pdf)
  2. Finding volume using LxWxH practice sheet and more practice (pdf)
  3. BrainPOP – Measuring Matter (link)

Featured Post: Hurricane Lessons & Resources

Image Source: NOAA Current Hurricane Activity

We are heading into Peak Hurricane Season, major hurricanes can still form although forecasts call for a below normal season (NOAA). 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).

All resources are listed below:

Task  15 – Hurricanes

  1. Record today’s Weather, yesterday’s Hi/Lo/Precipitation, & Astronomy Data (link) (excel).
  2. On your mini-map (pdf) record the following:
    • WSM (Weather Station Model pdf) – add it to the classroom map of the USA (pdf)
    • Precipitation (Rain – green, Snow – blue)
    • H/L/Fronts (link) or WunderMap (link)
    • MAPS: Click on Tropical (link)
      1. Check the box next to Hurricanes/Typhoons to view activity for the US
        • Using the color code under “Legend”, place a Hurricane symbol on your map to indicate the location of any current Hurricanes or Typhoons
        • There may not be any activity today
      2. Check the box next to Sea Surface Temperature
        • What is the approximate temperature for the water off the coast of New Jersey? Write the temperature on your mini map.
        • Does your adopted state touch a body of water?
          • If so, do the same for your adopted state.

Complete the following using the resources below:

  • BrainPOP Hurricanes Video (link) & Activity Sheets (link)
  • Hurricane Notes (pdf) –
    • How are hurricanes named?
    • Which storm was more destructive, Katrina or Sandy?
  • Tracking Hurricanes (spreadsheets)
    • Choose any one Hurricane and plot it on the NOAA/NWS Atlantic Basin Hurricane Tracking Chart (pdf)


  • Weather Guide pgs. 105-111 (link)
  • Hurricane Names (link)
  • NOAA/NWS Historical Hurricane Data (link) – Data for every Hurricanes, including maps
  • Weather Underground Hurricane Archive (link)
  • NOAA/NWS National Hurricane Center (link)
  • Interactive Activities
    • Create-a-Cane (link)
    • Aim a Hurricane (link)
    • Hurricane Tracker (link)
    • How Hurricanes Form (link)
    • NatGeo – Forces of Nature (link)
    • Saffir-Simpson Scale (link) – What happens when a hurricane hits your neighborhood?
  • Additional Resources:
    • Practice latitude and longitude: plotting hurricanes worksheet (pdf)
    • Hurricane Isabel 2003: tracking and analysis of Hurricane Isabel (pdf)

Elements, Compounds, and Mixtures Classification Activity

Screen Shot 2015-08-06 at 2.23.42 PM Materials

  • Elements, Compounds, and Mixtures –
    • Notes (pdf)
    • PPT Slides (ppt – read only access)
      • this ppt can be downloaded and saved to your computer, but not modified
      • click on ‘read only‘ to open the ppt after downloading
    • E, C, M, ? (pdf) – laminated or glued onto construction paper, cut apart, 1 set per group
    • Sorting/Task Cards and answers (pdf) – laminate and cut apart, 1 set per 2-4 students

Note: I modified this lesson to add a hands-on component with the addition of task cards that students can sort at their desks. I use this lesson as a group work activity to introduce Elements, Compounds, and Mixtures.


  1. Each group will have one set of task cards and one set of ECM? cards to hold up.
  2. Students will sort the items pictured into 4 columns: Elements, Compounds, Mixtures, and “?”. (The “?” category is a temporary place holder for students to discuss further within their group, all items should be sorted before answers are revealed)
  3. Once all the groups have had a chance to discuss and sort the items, we will go over the answers as a class.
  4. Using the ppt, show the first item (Rocks). Ask each group to choose one of the E,C, or M cards.
  5. Have them place the “?” in front of their answer. (this prevents the other groups from seeing their answer) A spokesperson for each group will stand up and hold the ECM? cards.
  6. Ask all the groups to reveal their answer at the same time. Compare answers & discuss.
  7. Reveal the answer and have students record the results in their notes.
  8. If needed, have students move the card to the correct category on their desk, too.
  9. For fun, I award a point to each group that has a correct answer, the kids enjoy a little friendly competition :).
  10. Continue with the next slide (Copper) and repeat.

For more lessons related to Chemistry, click on the Chemistry or Properties of Matter Tabs up above.

Free & Ready to Print: “I Can” Statements for NGSS and “Big Idea” Posters

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Update 9.9.15 – Link is updated

Ready to print, with a choice of backgrounds – thank you Science Class

  • “I Can” statements (link)
  • Big Ideas (link)

Mystery Footprints – Observation vs. Inference

Image Source: Teaching About Evolution and the Nature of Science (1998)


  • Updated for 2015 – Mystery Footprints – Observation vs. Inference (Google Slides Public link)
    • You can download this Google Slide Presentation in any format
      • Click “File” then “Download as” and choose ppt, etc
  • Handout for Mystery Footprint Activity (pdf)
  • projector


This is one of my favorite activities to practice making observations and inferences, it really helps the students differentiate between the two. As I mentioned in my ‘Boy in the Water‘ post, students tend to clump their observations and inferences together, they think they are the same thing.

For example, after viewing the first panel of the image, they will say that they ‘see two animals running towards each other.’ and my response is, “I don’t see two animals running towards each other, but I do see two sets of tracks”. After a few tries, they refine their answers and start to see the ‘facts’ of the image. Then we talk about the ‘story’ behind the facts.

When doing this activity, before I show them the first panel for the image, I stress how important it is not to share, or shout out, their thoughts or answers as soon as they see the image. Why is that important? Why can’t we share our answers right away? I stress to them that when they share their answers, they are taking away opportunities for their peers to think about what they are seeing.

For example, if someone asked you to name a vegetable, and I shouted out BROCCOLI, my answer would creep into everyone’s thoughts and BROCCOLI would push away any ideas about vegetables that didn’t have a chance to develop. Instead of sweet potatoes, or even yucca, you are now thinking about broccoli. It is important to let everyone have a chance to see the image, think about it, and to process and form their ideas. Their ideas may end up being the same as yours, but they may also think of something totally different. Once everyone has had a chance to process their thoughts, we can share our ideas and have a discussion where everyone can contribute and develop their thoughts further.

This activity was originally published in Teaching About Evolution and the Nature of Science (1998) and the book is available as a free download. You can find more details on pages 87-89 for this lesson.