Interactive
University of Colorado

University of Colorado: Ph Et Interactive Simulations: Balloons & Buoyancy

For Students 9th - 10th
Experiment with a helium balloon, a hot air balloon, or a rigid sphere filled with different gases. Discover what makes some balloons float and others sink.
Activity
PBS

Pbs Kids: Design Squad Challenge: Balloon Drive

For Students 3rd - 8th
Hands-on challenge "to make a helium balloon hover in one spot, then move it through an obstacle course using air currents". Provides full list of materials with ideas on how to design, build, and test the balloon's movement. Activity...
Article
How Stuff Works

How Stuff Works: How Helium Balloons Work

For Students 9th - 10th
This article explains how helium is able to keep balloons afloat in the air. Compares them to how hot air balloons work. Includes a video, and some activities to try for testing the principles being discussed.
Lesson Plan
Google

The Engineering Place: Balloon Flinking [Pdf]

For Teachers 3rd - 8th
A lesson plan and activity sheet on buoyancy. Students add weight to a helium-filled balloon to keep it suspended so that it won't float or sink, but instead will 'flink.'
Activity
Science Buddies

Science Buddies: An Uplifting Project: The Buoyancy of Balloons

For Students 9th - 10th
In this science fair project, measure the "lift" of a set of balloons and track how it changes over time as the helium escapes from the balloons. The Science Buddies project ideas are set up consistently beginning with an abstract,...
Unit Plan
TED Talks

Ted: Ted Ed: Helium: Periodic Table of Videos

For Students 9th - 10th
The team at periodicvideos has created a TED-Ed Lesson for every element of the periodic table. This one is about helium, Donald Duck voices, and floating balloons. [4:45]
Website
PBS

Pbs Learning Media: Buoyancy Brainteasers: Balloon in Car Puzzler

For Students 3rd - 8th
This interactive brainteaser from the NOVA: "Voyage of Doom" Web site challenges you to explain the behavior of a helium-filled balloon in a moving car.
Article
Other

Virtual Chembook: Density Applications With Gases

For Students 9th - 10th
DENSITY is a physical property of matter, as each element and compound has a unique density associated with it. Density defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume. For...