University of Waikato
Temperature, Salinity and Water Density
The difference between sinking and floating may be a little salt. Young experimenters analyze the effect of salt and temperature on the density of water. They use their results to predict the effect of climate change on ocean ecosystems.
University of Waikato
Buoyancy in Water
Change where an object floats in water. Pupils experiment with a Cartesian diver by squeezing on the side of a plastic bottle. Learners pay attention to the bulb of the pipette as the bottle is squeezed to determine what is happening...
American Chemical Society
Heat Up and Cool Down
Don't be so dense! Using food coloring, pupils conduct two experiments with the difference in densities of hot and cold water. In the first experiment, learners add dyed hot and cold water into room temperature water and observe how the...
NOAA
Please Pass the Salt
Salinity is the focus of two experimenters that work to answer the question, How does salt change the physical properties of water? Super scientists compare the freezing rate of salt and fresh water, combine the two waters to...
Museum of Science
Design a Submarine
Don't just sink the boat. Using a closed container as a submarine, pupils experiment to see what to add to the container to make it float, sink to the bottom, and hover in the middle. After finding one option, learners see if they can...
Discovery Education
Motion in the Ocean
How do temperature changes affect ocean currents? Scholars explore convection currents by demonstrating the flow of water in a baking dish. They use ice, heat, and food coloring to see currents. Then, they draw conclusions about their...
Illustrative Mathematics
Archimedes and the King's Crown
Learners will shout "Eureka!" in this quick but deep activity replicating the famous bathtub experiment of Archimedes. Given the scenario of a king with a suspected fake crown, young investigators develop formulas using density to...
Teach Engineering
Rock and Boat
Present the class with a question on whether the water level of a pond will rise they take a large rock out of a boat and drop it into the pond. Groups come down on all sides of the question and try to justify their answers. The activity...
American Chemical Society
All Wet
Sometimes liquids just don't get along together. A fun experiment has scholars determine whether various liquids dissolve in water. They pour isopropyl alcohol, vegetable oil, and corn syrup into cups of water to see which ones mix well...
Teach Engineering
Aerogels in Action
Model an oil spill cleanup. An engaging engineering lesson has groups using aerogels to simulate an oil spill cleanup (vegetable oil in water). Along the way, they learn about nanotechnology and hydrophilia/hydrophobia.
Teach Engineering
Buoyant Boats
Eureka! Using the clay boats made in the previous lesson, learners investigate the idea of buoyancy and water displacement to finish the last installment of five in a Floaters and Sinkers unit. Their observations during the activity...
Teach Engineering
Clay Boats
Clay itself sinks, but clay boats float. Why? Young engineers build clay boats to learn about buoyancy. They test the weight the boats can hold using washers and then tweak their designs to make improvements, following the engineering...
Colorado State University
How Far Away Is Space?
Outer space may be a lot closer than you think! Science scholars model the layers of the atmosphere using transparencies to gain insight into the scale of space. The resource includes ideas to tailor the activity to the skill level of...
Museum of Science
Museum of Science: Water Density Experiment
A simple lab activity to demonstrate that ocean currents are influenced by changes in water density.
American Chemical Society
Inquiry in Action: Changing the Density of a Liquid: Heating and Cooling
In this activity, students will investigate whether the temperature of water affects its density. Students will place colored hot and cold water in a cup of room-temperature water to see that cold water sinks while hot water floats. Then...
Science Fun for Everyone
Science Fun: Water Fireworks
In this science experiment, you will learn about density while making water fireworks!
Other
Lapeer County Schools Science Resources: Density Lab
A simple lab experiment for students to find the density of two solids and a liquid (does not use water displacement). Note that number 1d should not state "weighs" since mass is being found.
PBS
Pbs Teachers: Hot and Cold Water Experiment
Demonstrate the relationship between water temperature and density using two clear plastic soda bottles.
Hunkins Experiments
Hunkin's Experiments: See if a Ring Is Pure Gold
Hunkin's Experiments is a group of simple cartoon illustrations of scientific principles. Some would work well in the classroom, but others have little value beyond entertaining students. All of the projects are easy to do. This one...
Other
Steve Spangler Science: Denver's Brown Cloud
Learn how fluids move through our atmosphere and water. This experiment explains atmospheric convection currents (thunderstorms), the Gulf Stream, and temperature inversion. A video is included.
SEDL
Oceans [Pdf]
This large PDF file integrates math, science, and language into several lessons about characteristics of the oceans. Topics include ocean currents, tides, density, marine life, and pollution.
Science Education Resource Center at Carleton College
Serc: Layering Liquids
A lab activity to show students how different densities of liquid layer on top of each other by using four different colored liquids that contain different levels of salinity. This activity can also be used in an ocean unit where...
TeachEngineering
Teach Engineering: Anchors Away
In this activity, the students will discover the relationship between an object's mass and the amount of space it takes up (its volume). The students will learn about the concept of displacement and how an object can float if it...
Scholastic
Scholastic: Dirtmeister's Science Lab: That Sinking Feeling
Simple experiments dealing with water temperature and density that you can complete in the lab and at home.