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Explore some properties of water with the Amoeba Sisters! It's all about those hydrogen bonds. Terms discussed include adhesion, cohesion, surface tension, specific heat - all made possible by those amazing hydrogen bonds.

In this video Paul Andersen discusses the technology, advantages and disadvantages of six sources of renewable energy; biomass, hydroelectric, solar, geothermal wind, and hydrogen. He also explains how changes in the storage and flow of energy in our power grid must be improved. He also lists the energy returned over energy invested ration for the various forms of energy.

Chemist Daniel Nocera of Harvard University and his team joined forces with synthetic biologist Pamela Silver of Harvard Medical School and her team to craft a kind of living battery, which they call a bionic leaf for its melding of biology and technology. The device uses solar electricity from a photovoltaic panel to power the chemistry that splits water into oxygen and hydrogen.

Methane's potency is one reason why environmentalists are so concerned about natural gas leaks. The Porter Ranch disaster in southern California spewed more than 200 million pounds of methane before it was finally plugged in mid-February. But each year, cows in the U.S. burp out 65 times more gas than was released in the now infamous leak. Globally, about a quarter of methane pollution comes from livestock. Hristov and his team study ways to reduce those emissions, so they have gotten very good at quantifying the amount their cows exhale. Prompted by some extra snacks, cow number 2050 ducks her head into a hooded machine that records the amount of methane, hydrogen, and carbon dioxide in her burps. During experiments, the scientists take eight measurements from each cow over several days. In a few months, this gives a snapshot of just how much methane the animals churn out -- and whether particular interventions work to slash that pollution.

This case study presents the story of "Nick," a student who has been assigned the task of writing a research paper describing the fundamentals of chemical bonds and how they relate to human life. When Nick experiences difficulty remembering information about the different types of chemical bonds, he turns to his tutor, Josh, for help. Josh explains orbitals and valence electrons to Nick, and then they together review nonpolar and polar covalent bonds, ionic bonds, and hydrogen bonds. A final practical application exercise requires that students write about how different types of chemical bonds may relate to the development of Alzheimer's disease and to the mechanism of action of potential drug treatments.  The case is presented with PowerPoint slides and is designed to be used with a personal response system ("clickers"), but students can instead record their answers on paper or share them verbally.  The content is appropriate for use in high school and undergraduate introductory chemistry and biology courses.

This interrupted case study examines basic concepts of chemical bonding by telling the story of "Madison," a young girl eager to learn how her hair can transition from natural curls to straight, smooth tresses. The case can be used to teach or review the major categories of bonds (ionic, covalent and hydrogen), major macromolecules of life, and hydrolytic and dehydration reactions. It also explores how chemical relaxers and heat through blow drying and flat-ironing can change the nature of straight, wavy and curly hair through the disruption of protein shape. Students will thus learn what it means when a protein has become denatured and how various variables such as pH, heat and salts can lead to the unraveling of the three-dimensional shape of proteins. This case is suitable for an AP high school course, or for an introductory biology or chemistry course for majors or non-majors. This activity can also be used as a review of basic biology and chemistry for students in an upper-level biochemistry course.

It's an inevitable side effect of longevity: your hair will turn gray. In this episode, Sophia Cai chats about the chemistry of your natural hair color, why it eventually turns white, and how scientists may be able to slow that graying down.