To float or not to float

To begin the new chapter on Density and Buoyancy, we completed the Coke vs. Diet Coke density demo.  We decided to include Coke Zero in our demo to extend our line of questioning.

Before we started the demo, I asked students to make observations about each can. Students made sure to look carefully at the volume (355mL), as well as the ingredients in the soda.  We were quick to notice that Coke had 42g of sugar while Diet Coke and Coke Zero had none.

The demo is simple: place each 355mL can of Coke, Diet Coke, and Coke Zero into a large basin of water, and observe.  We each made a hypothesis about which cans would float and/or sink.  

Each class had varying hypotheses; some where closer than others. So, what were the results?

Coke sunk to the bottom, while Diet Coke and Coke Zero stayed afloat.  Why was that?

Simply put...density!  We learned that the density of water is 1g/cm3.  Therefore, the can of Coke had a greater density than water, while the cans of Diet Coke and Coke Zero had smaller densities.  We found out that the amount of sugar (high fructose corn syrup) in the regular can of Coke increased the mass of the can, while the tiny amount of artificial sweetener (aspartame) in Diet Coke and Coke Zero did not change its mass too much.

We used the following formula (Density = Mass/Volume) to calculate each can's density.  We learned that if the mass is greater than the volume, it will have a greater density; whereas if the mass is smaller than the volume, it will have a smaller density.

And so it begins...

A delayed greeting to all!

Welcome to Miss Lee's classroom blog.  It is here that I will be sharing and reflecting on interesting lessons, activities and challenges that our grade 8 students work through.  

Our study of science is based on challenges and activities that promote inquiry-based learning.  We hope to thrive in a learning environment that asks questions, collaborate with one another, extend our thinking, and make connections between what we know and how we can apply our knowledge to the real world.

As we're coming to an end with our Fluids unit, the next few posts will highlight some of the concepts, activities, and challenges we've completed to support our learning.