Density Column for Little Kids
Overview
Density columns are a great way to introduce kids to mass, volume, and density! With hands-on activities, kids can see how liquids float or sink based on their density. They can also experiment with objects around them by adding them to the density column and watching them float or sink.
How do we make a density column?
We can make a density column by pouring different liquids into a cup and seeing how they float or sink compared to other liquids in the cup. We can also put things into the cup to guess their density by seeing where they stop sinking.
We will need:
1/4 measuring cup
Plastic, clear cup (that you can see through)
Water
Dawn dish soap
Vegetable Oill
Milk
Corn Syrup (or honey)
Rubbing alcohol
Food coloring
One lego
One penny
Something small like a cherry
What is density?
Density is the mass of an object compared to it's volume.
(The mass is how much matter is in an object).
(The volume is the amount of space an object takes up).
If an object is small and heavy, it has a high density. If an object is big and easy to pick up, it has less density.
Is this the same as weight? No. If you weighed yourself on earth, you might weigh 75 pounds. But if you weighed yourself on the moon (which has less gravity), then you would weigh less. But you would still have the same mass.
Imagine a balloon. It is big and light, it has less density.
Now imagine that same size balloon, but it's a rock. It has more density.
Density of water example
Let's say the first box is air. It has some molecules of water, but not much. It has low density.
The second box is water. It has more water molecules, but they move around easily. This is more dense than air.
The third box is ice. It is full of water molecules. They are so compact they do not move around easily. It has high density.
What about different liquids?
Water is a liquid with a density of 1.0 (g/ml).
Do all liquids have that same density? No!
Something that is fun about science is realizing how things are different.
Different liquids have different densities.
If something has more density, it is heavier and sinks.
If something has less density, it is lighter and floats.
Is this why oil floats? Yes!
The density of oil is 0.92 (g/ml). That is less density than water.
Let's have fun
We can find an object's density by dividing the mass by the volume. The formula looks like this:
Density = mass/volume
In this project, we will use grams divided by milliliters (g/ml).
For fun, we will give you the density of the liquids:
Water = 1.0 (g/ml) (add the food coloring to the water)
Dawn dish soap = 1.06 (g/ml)
Vegetable Oil = 0.92 (g/ml)
Milk = 1.034 (g/ml)
Corn Syrup (or honey) = 1.48 (g/ml) or 1.44 (g/ml) for honey
Rubbing alcohol = 0.7854 (g/ml)
Use a piece of paper and write down the most dense liquids to the least dense liquids.
What do you think is going to happen?
Experiment time
Get a 1/4 measuring cup.
First, add the most dense liquids slowly to the clear cup. (Starting with corn syrup or honey).
Then add the liquids slowly while tilting the cup to the side.
Make sure you add them from high density (most dense) to low density (least dense)
Adding toys
Now that your cup has layers of liquids, lets add toys and guess their density!
Carefully drop a penny in the cup.
What did it do?
Did it sink to the bottom? Yes!
Because a penny has a density of 7.2 (g/ml)
That is more density than all the liquids!
Now carefully add a lego (about the same size as a penny)
What did it do? Did it float?
Why?
What liquids are more dense than a lego?