Have you ever passed a pond or swamp and seen bugs walking on the water? Find out how they do it in this Smithsonian Lightning Lesson.

In this episode of Crash Course Chemistry, Hank gives you the low down on things like London Dispersion Forces, Hydrogen Bonds, Cohesion, Adhesion, Viscosity, Capillary Action, Surface Tension, and why liquids are just... WEIRD!

Chapters:
London Dispersion Forces
Dipole-Dipole Forces
Hydrogen Bonds
Cohesion
Adhesion
Viscosity
Capillary Action
Surface Tension

Students are introduced to a unique fluid ferrofluids the shape of which can be influenced by magnetic fields. This activity supplements traditional magnetism activities and offers comparisons between large-scale materials and nanomaterials.Students are introduced to the concepts of magnetism, surfactants and nanotechnology by relating movie magic to practical science. Students observe ferrofluid properties as a stand-alone fluid and under an imposed magnetic field. They learn about the components of ferrofluids and their functionality as they create shapes using magnetically controlled ferrofluids and create their masterpieces.

In this fun, engaging activity, students are introduced to a unique type of fluid ferrofluids whose shape can be influenced by magnetic fields! Students act as materials engineers and create their own ferrofluids. They are challenged to make magnetic ink out of ferrofluids and test their creations to see if they work. Concurrently, they learn more about magnetism, surfactants and nanotechnology. As they observe fluid properties as a standalone-fluid and under an imposed magnetic field, they come to understand the components of ferrofluids and their functionality.

Students observe capillary action in glass tubes of varying sizes. Then they use the capillary action to calculate the surface tension in each tube. They find the average surface tensions and calculate the statistical errors.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"If you take your coffee black, you’re likely missing out on one of the most curious displays in fluid dynamics. Though well known to science as delayed coalescence , this phenomenon is poorly understood. Now researchers from MIT have discovered how and why it occurs. And the results could help scientists understand important fluid dynamic effects that lie beyond their morning cup of joe. Since the 1960s, researchers studying coalescence have examined the roles played by properties like density, surface tension, viscosity, and surface charge. Early on, it was discovered that drops levitating on a fluid bath actually rest on a cushion of air. But it remained unclear just how long that air cushion could be sustained before collapsing under the weight of the drop. To address that problem, the MIT researchers focused on one often overlooked property: temperature—specifically, the temperature difference between a drop and a fluid bath..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This course introduces the basic ideas for understanding the dynamics of continuum systems, by studying specific examples from a range of different fields. Our goal will be to explain the general principles, and also to illustrate them via important physical effects. A parallel goal of this course is to give you an introduction to mathematical modeling.

Students investigate the property dependence between liquid and solid interfaces and determine observable differences in how liquids react to different solid surfaces. They compare copper pennies and plastic "coins" as the two test surfaces. Using an eye dropper to deliver various fluids onto the surfaces, students determine the volume and mass of a liquid that can sit on the surface. They use rulers, scales, equations of volume and area, and other methods of approximation and observation, to make their own graphical interpretations of trends. They apply what they learned to design two super-surfaces (from provided surface treatment materials) that arecapable of holding the most liquid by volume and by mass. Cost of materials is a parameter in their design decisions.

Part One of this video lesson will explore the science that explains soap bubbles, as well as the application of this knowledge to other areas, such as architecture and biology. We first introduce the concept of surface tension. In Part Two of this video lesson, students will learn where the colors of soap bubbles come from and also learn what soap bubbles and telescopes have in common. The students will first make a connection between light and waves waves and will then go on to explore various characteristics of waves through a series of classroom activities.

Student teams are challenged to evaluate the design of several liquid soaps to answer the question, “Which soap is the best?” Through two simple teacher class demonstrations and the activity investigation, students learn about surface tension and how it is measured, the properties of surfactants (soaps), and how surfactants change the surface properties of liquids. As they evaluate the engineering design of real-world products (different liquid dish washing soap brands), students see the range of design constraints such as cost, reliability, effectiveness and environmental impact. By investigating the critical micelle concentration of various soaps, students determine which requires less volume to be an effective cleaning agent, factors related to both the cost and environmental impact of the surfactant. By investigating the minimum surface tension of the soap, students determine which dissolves dirt and oil most effectively and thus cleans with the least effort. Students evaluate these competing criteria and make their own determination as to which of five liquid soaps make the “best” soap, giving their own evidence and scientific reasoning. They make the connection between gathered data and the real-world experience in using these liquid soaps.

Students learn about the properties of solutions—such as ion interactions, surface tension and viscosity—as they make their own soap and shampoo and then compare their properties. Working as if they are chemical engineers, they explore and compare how the two surfactants behave in tap water, as well as classroom-prepared acidic water, hard water and seawater using four tests: a “shake test” (assessing the amount of bubbles produced), a surface tension test, a viscosity test, and a pH test. Then they coalesce their findings into a recommendation for how to engineer the best soap versus shampoo. The activity may be shortened by using purchased liquid soap and shampoo from which students proceed to conduct the four tests. A lab worksheet and post-quiz are provided.

Have you ever wondered how some insects are able to "skate" on the surface of water? We will learn about how intermolecular forces make this possible. We will also cover liquids, solids, mixtures, and phase changes.

Through two lessons and their associated activities, students do the work of scientists by designing their own experiments to answer questions they generate. Through a simple activity involving surface tension, students learn what a hypothesis is—and isn't—and why generating a hypothesis is an important aspect of the scientific method. In the second activity, with bubble gum to capture their interest, students learn to design and conduct controlled experiments to answer their own questions about the amounts of sugar (or artificial sweetener) in bubble or chewing gum.

Students are introduced to superhydrophobic surfaces and the "lotus effect." Water spilled on a superhydrophobic surface does not wet the surface, but simply rolls off. Additionally, as water moves across the superhydrophobic surface, it picks up and carries away any foreign material, such as dust or dirt. Students learn how plants create and use superhydrophobic surfaces in nature and how engineers have created human-made products that mimic the properties of these natural surfaces. They also learn about the tendency of all superhydrophobic surfaces to develop water droplets that do not roll off the surface but become "pinned" under certain conditions, such as water droplets formed from condensation. They see how the introduction of mechanical energy can "unpin" these water droplets and restore the desirable properties of the superhydrophobic surface.

Students experiment and hypothesize about surface tension and cohesion, using water, ground black pepper, liquid soap, and other household products.

Surface tension accounts for many of the interesting properties we associate with water. By learning about surface tension and adhesive forces, students learn why liquid jets of water break into droplets rather than staying in a continuous stream. Through hands-on activities, students learn how the combination of adhesive forces and cohesive forces cause capillary motion. They study different effects of capillary motion and use capillary motion to measure surface tension. Students explore the phenomena of wetting and hydrophobic and hydrophilic surfaces and see how water's behavior changes when a surface is treated with different coatings. A lotus leaf is a natural example of a superhydrophobic surface, with its water-repellent, self-cleaning characteristics. Students examine the lotus effect on natural leaves and human-made superhydrophobic surfaces, and explore how the lotus leaf repels dewy water through vibration. See the Unit Overview section for details on each lesson in this unit.

Students are presented with the question: "Why does a liquid jet break up into droplets?" and introduced to its importance in inkjet printers. A discussion of cohesive forces and surface tension is included, as well as surface acting agents (surfactants) and their ability to weaken the surface tension of water. Students observe the effects of surface tension using common household materials. Finally, students return to the original question through a homework assignment that helps them relate surface tension and surface area to the creation of water droplets from a liquid jet.

Students extend their understanding of surface tension by exploring the real-world engineering problem of deciding what makes a "good" soap bubble. Student teams first measure this property, and then use this measurement to determine the best soap solution for making bubbles. They experiment with additives to their best soap and water "recipes" to increase the strength or longevity of the bubbles. In a math homework, students perform calculations that explain why soap bubbles form spheres.

In an activity that integrates science and art, students see, experience and harness the phenomenon of surface tension as they create beautiful works of art. Students conduct two experiments related to surface tension floating objects on the surface of water and creating original artwork using floating inks. They also learn historical and cultural information through an introduction to the ancient Japanese art form of suminagashi. They take the topic a step further by discussing how an understanding of surface tension can be applied to solve real-world engineering problems and create useful inventions.