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## Temperature, Density, a Science Song!

I love Section 3.6 for a couple of reasons.

The first is that the demonstration at the beginning of the lesson is one that hooks the kids right away. We actually have an apparatus that allows us to put hot water all on one side of the container, and cold water on the other side. Then, we remove the divide and watch the hot water (colored yellow) go to the top and the cold water (colored blue) sink to the bottom. The students all ‘Ooh!’ and ‘Aah!’, and many of them record the experiment using their iPads for a future showing at home.

The second reason I love this activity is because it quickly makes a relation to information that students learned in Chapter 2 about how heating a substance will increase the spacing between molecules. Only in this chapter, we take it a step further and determine that as a result of heating the object, it will have a slightly smaller density than it did before due to the slight increase in volume.

I make sure to show this mathematically to the class, as some of them will understand it better through numbers. Others really take the experiment to heart with the pipettes putting colored hot and cold water into room temperature water. Make sure that you make the liquids pretty colored with food coloring in order for your class to see the proper result. For my set-up, I have a two beakers of cold and hot water at the front with a lot of pipettes in each. They can just come and take a pipette full of the temperature water. This way, the only main direction I have to tell them is to make sure to avoid cross-contamination when returning the pipettes.

Another reason I love this lessons is the Extend portion of the activity. It really shows a great application of the lesson in the real world, and we will talk about it again when we talk about the science and worries of climate change in the spring with our 7th grade interdisciplinary unit.

Finally, because we have reached the end of a chapter, it’s time for a new science song! This song is called ‘Denser’, to the tune of “Royals” by Lorde!

(Note: When it says Quest, I call all my assessments in class Quests for Success. Just some context ðŸ™‚ )

Denser

Iâ€™ve always wondered about density
Relating mass to volume was so boring
And then I went to science class
Then I realized, how great it could be

Â And Mr. Chapmanâ€™s like â€˜mass and size and arrangement of atoms
Determine the density of objects
Yes indeed, we can calculate density
And everybodyâ€™s like, divide mass by volume of the sample
Grams per c-m cubed is the example
We must care, to do well in this science affair

Â What makes an object denser (denser)
Its atoms could be small,
Or maybe they are tightly packed
On a mass level they may be stacked

Densityâ€™s our ruler (ruler),
You can call it Queen D
And with it weâ€™ll pass (weâ€™ll pass, weâ€™ll pass, weâ€™ll pass)
And do well on the Quest

My friends and Iâ€”we’ve cracked the code
We know if objects float or sink in the water
1 gram per cubic centi-meter
Less dense things float
More dense things will sink

And Mr. Chapmanâ€™s like â€˜mass and size and arrangement of atoms
Determine the density of objectsâ€™
Yes indeed, we can calculate density
And everybodyâ€™s like, divide mass by volume of the sample
Grams per c-m cubed is the example
We must care, to do well in this science affair

What makes an object denser (denser)
Its atoms could be small,
Or maybe they are tightly packed
On a mass level they may be stacked

Densityâ€™s our ruler (ruler),
You can call it Queen D
And with it weâ€™ll pass (weâ€™ll pass, weâ€™ll pass, weâ€™ll pass)
And do well on the Quest

Ooh ooh oh
But what about temperature
It affects density for sure
Ooh ooh oh
Heating equals less dense things
Weâ€™ve gotta think about the spacing

What makes an object denser (denser).
Its atoms could be small,
Or maybe they are tightly packed
On a mass level they may be stacked

Densityâ€™s our ruler (ruler),
You can call it Queen D
And with it weâ€™ll pass (weâ€™ll pass, weâ€™ll pass, weâ€™ll pass)
And do well on the Quest

Michael teaches 7th and 8th grade science in Boston, Massachusetts.