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

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.

Explains the basic principles of the Bohr hydrogen atom.

A free CK-12 account is required to view all materials.

At this site from the Nobel e-Museum you can download and read Niels Bohr's Nobel Lecture, "The structure of the atom" (available in pdf format).

This resource presents a biography of Bohr, including many personal tidbits, as well as a substantial treatment of his scientific work. Several interesting quotes by and about Bohr are included. It also links to several other sources.

The Nobel Foundation provides this site about Niels Bohr's contributions to the world of physics, specifically his "investigation of the structure of atoms and of the radiation emanating from them." This biography includes information on his education and personal life, as well.

This Nobel Foundation site provides the "Presentation Speech by Professor S.A. Arrhenius, Chairman of the Nobel Committee for Physics of the Royal Swedish Academy of Sciences, on December 10, 1922."

A wonderful PBS biography of a great man. This contains many personal touches, yet does a fine job of describing Bohr's scientific work. But it's best at Bohr the man. Nice quotes, one in the middle, one at the end.

Become a game show contestant in this online activity from A Science Odyssey and ask a series of questions to a panel of mystery scientists, using the answers to determine which scientist is Einstein.