Students define and classify alloys as mixtures, while comparing and contrasting the properties of alloys to those of pure substances. Students learn that engineers investigate the structures and properties of alloys for biomedical and transportation applications. Pre- and post-assessment handouts are provided.

Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Define matter and elements
Describe the interrelationship between protons, neutrons, and electrons
Compare the ways in which electrons can be donated or shared between atoms
Explain the ways in which naturally occurring elements combine to create molecules, cells, tissues, organ systems, and organisms

In this video, Paul Andersen explains how elements and molecules are made of atoms. In a pure sample of a pure substance the average mass remains the same. If more than one atom is found in a molecule the ration of average masses remains the same. [6:08]

This site provides a detailed overview of atoms. Content explores an atom's structure, as well as what ions are, how atoms bond, what compounds are (including how to name compounds), and what isotopes are.

Here you can find out about hydrogen, the first element in the periodic table. Content includes shell information, where to find it in nature, and why it is helpful to us.

Here you can find some great information about the 7th element in the periodic table, "nitrogen." Content focuses on nitrogen's electrons, where you can find nitrogen in nature and in the home, and how nitrogen combines with other elements.

Set of tables describing many physical and chemical properties of the element vanadium.

Chemical reactions are the foundation of chemistry, and understanding how elements combine and in what ratios helps us to understand the world around us. This pathway provides resources about how different chemicals react, and the ratios in which they react, a field of study known as Stoichiometry (literally: element measuring).

A set of tables summarizing the physical and chemical properties of the element selenium.

Covers compounds and chemical change.

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Covers element and properties of an element.

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This lesson will introduce the systematic classification of matter used in chemistry, defining the terms heterogeneous, homogeneous, pure substance, mixture, compound, element and providing examples.

This is the tenth in a series of articles designed to help the new novel author. This article focuses on how to develop characters through their actions instead of simply relying on dialogue and description of thoughts. W.11-12.3d Sensory/precise lang narratives, W.9-10.3b Narrative techn

Students learn what the forms of mercury are, the sources, how to reduce the releases, and how it affects humans and the environment.

To gain an understanding of mixtures and the concept of separation of mixtures, students use strong magnets to find the element of iron in iron-fortified breakfast cereal flakes. Through this activity, they see how the iron component of this heterogeneous mixture (cereal) retains its properties and can thus be separated by physical means.

Students gain a better understanding of the different types of materials as pure substances and mixtures and learn to distinguish between homogeneous and heterogeneous mixtures by discussing an assortment of example materials they use and encounter in their daily lives.