Science for kids is one of our favorite subjects! We’ve done a lot science experiments for kids Today, we will show you an extremely simple way to make a liquid density experiment. We’ve done other types of liquid density experiments for kids before, but this time, we decided to try and make a density jar that mimics the layers of the ocean!
Kids will have a blast with ocean science experiments just like this one!
Ocean Layer Density Experiment
Follow these directions to learn how to make your own liquid density experiment that mimics the layers of the ocean.
Liquid Density Experiment Hypothesis
In addition to learning about the ocean layers, you can explore the density of different liquids in this activity. Discuss what liquid the children think might be the most and least dense.
What is Density in Science?
Different liquids have different densities based on their weight. A cup of oil, for example, will weigh a little less than a cup of syrup.
Liquids with the highest density will sink to the bottom of a cup, while liquids with a lower density will rise to the top.
In general, density is how many particles are inside each liquid. In an equation, density equals mass divided by volume.
When the mass of an object increases but the volume stays the same, the density increases.
What are the Layers of the Ocean?
Don’t miss the Cartesian diver experiment!
The ocean has several different layers, but there are three main layers, which we represent here.
The surface ocean: This is warm and where a lot of sea life hangs out. The sun lights up this part of the ocean. The surface ocean takes up the top 200 meters of the ocean.
The thermocline ocean: The thermocline is the area of the ocean where the temperature drops rapidly and the density increases quickly. This layer starts at 100 meters and transitions to the deep ocean. The deeper in the thermocline layer you are, the colder it is.
The deep ocean: This is the majority of the ocean (about 90%). It varies in depth, but often still has a lot of ocean life living in it. It is cold and dense. It is typically just above freezing. The deep ocean starts at about 200 meters deep, but can be deeper than 1,000 meters.
How to Turn this Science Activity into a Science Fair Project
TO make any science demonstration into a science fair project, all you have to do is have a question and some variables to gest.
You can take this experiment one step further by dropping a variety of household objects of various weights into the liquids. Let your children guess where they think the objects will settle. Use objects like:
- Plastic beads
- Bottle caps
- Plastic bottle caps
- Safety pin
- Metal nuts or screws
Denser objects will fall further down the column of liquids (some may fall all the way to the bottom), while less dense objects will stop somewhere along the way. You can use this as an easy way to compare the density of a liquid to a solid.
Record the results and then you have a fun addition to classic science fair projects for kids!
What you need to do the Ocean Layer Density Experiment
- 3 separate clear containers (we used mason jars)
- 1 large container
- A heavy liquid (could be honey, corn syrup, or molasses)
- Vegetable oil
- Food coloring
What You Need for a Science Fair
You’ll want to have these supplies on hand before doing your science fair project. Shop the included Amazon storefronts to make things easier and don’t forget to download the free science fair planning checklist before getting started!
Science Fair Project Planning
When you’re planning your project, you want to keep everything organized. Click the image below to get my free science fair project checklist so you can start organizing your project from the start.
You may also want to check out this list of science fair project research supplies.
Supplies for a Science Fair Project
There are so many supplies for science fair projects that are individual to each project, but if you want a general list of possible supplies and inspiration for your project, check out my selection of science fair experiment supplies on Amazon.
Supplies for a Science Fair Presentation
Your science fair presentation is important! It should look presentable and eye-catching. Check out this list of my favorite science fair presentation supplies.
How to Do the Density Jar Science Fair Project
Pour about a cup of each of the liquids into the three individual containers. Use less if you have smaller containers. We decided to dye our water blue, but it ended up blending in with the dark color of our molasses.
Have the children guess what liquid will rise to the top. Record the guesses on your density sheet.
Pour all the liquids into a single jar and wait for them to separate. It shouldn’t take more than a minute or so. See if your guesses were right, or if you were wrong. Talk about what makes a liquid denser than its fellow liquids.
Discuss how the jar represents the layers of the ocean. As the ocean gets deeper and darker, you can see the distinct layers of the ocean represented in your jar.
Label each layer of the ocean and discuss what animals and fish live in each layer of the ocean.