US Department of Agriculture
Sink or Float?
Will it sink or will it float? Learners predict the outcome as they drop random objects into a container of water. Then, they keep track of the results and record the data in a t-chart to draw a final conclusion.
Exploratorium
Descartes' Diver
Pique interest in water pressure, demonstrate buoyancy, and explore water displacement concepts with a homemade Cartesian diver. You may want to change the name of the toy, however, as is is not documented the Rene Descartes...
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...
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.
DiscoverE
Water Sampling
What is the best way to test water quality? Using plastic bottles, scholars create monitoring sensors to test water quality. Creating three different sensors allows individuals to measure water quality at different water levels.
It's About Time
Mass and Volume
Don't be so dense that light bends around you; study the relationship between mass and volume instead. Young chemists measure the density of a variety of liquids and solids. A reading passage and analysis questions introduce pupils to...
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...
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...
DiscoverE
Action Figure Diver
Will your next buoyancy lab rise to the occasion? Make a splash with action figure divers! Teams of young physicists explore the relationship between mass and buoyancy by adding weights or balloons to achieve a diver that neither sinks...
Royal Society of Chemistry
A Cartesian Diver—Classic Chemistry Experiments
Sometimes the simplest experiments leave the biggest impression! Introduce young chemists to the Cartesian Diver by having them make one of their own. Use the Diver to further their study of liquids and gases, as well as compression.
PBS
Reading Adventure Pack: Oceans
Flotsam by David Wiesner and The Magic School Bus on the Ocean Floor by Joanna Cole, illustrated by Bruce Degen, begin a reading adventure pack focusing on oceans. With story listening and thoughtful discussion, scholars complete several...
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
Determining Densities
Don't be dense—use a robust resource. The second installment of a five-part Floaters and Sinkers unit has learners determine the densities of several objects. As part of the activity, they learn the displacement method for finding...
DiscoverE
Design a Flotation Device
Save the soup! Scholars devise a flotation device using straws, balloons, foam, corks, and other objects. A can of soup must stay afloat for at least a minute with this device—your dinner might depend on it!
Center for Learning in Action
Properties of Balls
Enhance your states of matter lessons with a hands-on science investigation that compares six different balls' color, texture, size, weight, ability to bounce, and buoyancy.
Exploratorium
Bubble Suspension
Create a cushion of carbon dioxide gas to float some soap bubbles on. Many concepts can be demonstrated through this activity:
Carbon dioxide gas is more dense than air
Bubbles are semipermeable, allowing only carbon dioxide to diffuse...
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...
PBS
Watercraft
Whatever floats your boat—with some additional weight. The first activity in a five-part series challenges pupils to design a boat to hold pennies. Using the design process, learners design, build, and test their boats, making sure they...
American Chemical Society
Inquiry in Action: Compare the Density of an Object to the Density of Water
In this activity, students use tea light candle holders and a student-made balance to compare the weight of equal volumes of wax, water, and clay. Students will discover that since the wax weighs less than an equal volume of water, it is...
Science Buddies
Science Buddies: How Much Weight Can Your Boat Float?
Have you ever wondered how a ship made of steel can float? In this project you'll investigate how much weight boat hulls of various shapes and sizes can support without sinking.
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...
Museum of Science
Museum of Science and Industry: Online Science: Design a Submarine
Become an engineer, and design a submarine that moves in the water like a real submarine. Try making it sink, float, and hover in the water.
Science is Fun
Fun Science: Bowling Balls: Sink or Float?
For a dramatic illustration of density check out this demonstration. It's simple to do, only requiring a bowling ball and some water.