Atomic Structure of an Alloy Learn about the atomic structure of bronze, a copper alloy, in this video excerpt from NOVA: "Hunting the Elements."
Bend, Twist and Break: Beyond the Laboratory Dr. Chris Muhlstein explains that when scientists study fracture surfaces from controlled experiments to understand the resulting shapes and features, they can use their understanding to deduce what happened when they were not around to see the material fail or break. Further they can predict what will have to a larger or smaller piece of material under stress. This process is how scientists and engineers translate a lab experiment into a design for an airplane, bridge or even a bike frame.
Bend, Twist and Break: Breaking Glass Dr. Chris Muhlstein explains that researchers learn about the scientific basis for failure of materials by running experiments in the lab, using a simple shape like a glass rod to calculate the strength of material and predict its failure. The same tests can be done at the micro and nano scale using tiny specimens. Students can run a similar experiment with a bar of chocolate.
Bend, Twist and Break: Fracture Surfaces Dr. Chris Muhlstein explains that fracture surfaces can reveal how and why a material has failed. An image of a fracture surface has features or shapes that we can use to understand where a material failed and why. Scientists use an optical microscope or a scanning electron microscope to read a fracture surface at high magnifications, much like we read maps to find our way.
Bend, Twist and Break: The Bridge Dr. Chris Muhlstein explains that the arrangement of atoms in a material determines the properties. He drops an iPod to illustrate how the arrangement of atoms can protect it from damage; he narrates footage of the collapse of the Tacoma Narrows Bridge in the 1940s to show how the deformation of materials can cause the collapse of a structure.
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Matter: Physical and Chemical Properties (Video)How are substances identified? There are two major ways we can describe a
substance: physical properties and chemical properties. Learn about how chemists use properties to classify matter as either a mixture or a pure substance. What Are Elements? (Video)Look around you. What do you see? Elements are everywhere. They are the
building blocks of all matter on Earth. In this lesson, we will discuss what an element is, how elements are written as symbols, and how elements are the building blocks of all matter. Atomic Number and Mass Number (Video)Atoms are the basic building blocks of everything around you. In order to
really understand how atoms combine to form molecules, it's necessary to be familiar with their structure. In this lesson, we'll dissect atoms so we can see just what really goes into those little building blocks of matter. Dissolving Salts in Water In this interactive activity adapted from Iowa State University, design and carry out an experiment: dissolve salts in water, see how different ionic compounds produce different reactions, and observe the resulting changes in temperature.
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"Order, Atomic Structure, & Properties"
Unit Understandings & Goals:
Order can be found in atomic structure.
Changes in this order, are the results of energy changes in the system.