Exploring Density’s Role in our Grade 6 Earth Science Study

We’ve done this lab before in her Chemistry Block for G3, but you know how I feel about repeating things – it’s a great idea! Density plays such a big role in the formation of the Earth and of the Earth’s atmosphere. I felt we needed a quick review of this concept, so we repeated this lab. See video of our process at the end.

We started off with solids – cotton balls and chickpeas – filling a container that was the same size and then weighting both. They obviously had very different weights, so I posed the questions, “Why?” If they occupy the same amount of space, why wouldn’t they have the same weight? This led us into a discussion about density, where she used her words to describe what was going on. Then we looked at the definition of density.

Density: the amount of something that fits into a given space.
(the relative lightness or heaviness of an object compared to the space it occupies)

Then we talked about density of different states of matter. What happens when something is less dense? It floats. Oil floats on water. Helium balloons float, because they are less dense than air.

Knowing this, we compared a series of liquids to see which floated on which. These liquids were: honey, Karo syrup, liquid dish soap, olive oil, water, and rubbing alcohol. We colored most of these with food coloring so that we could see the layers more clearly. The glass vials we used were the ones purchased for our botany lab. It worked best to slowly pour the more viscus liquids, honey, karo syrup, and dish soap, and to use a pipet for the other liquids.

To finish, we layered them from the densest to the least dense based on our earlier comparisons, giving us a density column. In our previous lab, we then ‘tested’ different object’s density by placing them in the density column to see where they ‘landed.’ For that we used a much bigger density column. For this review, we just ended with our density column. 

You can see our previous lab with far more detail in my G3 Chemistry Block high lights on Instagram. 

Video of our Process

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