This site is a searchable encyclopedia of thousands of photos, descriptions, sound recordings, and other information about individual animal species. Find out about amphibians, arthropods, birds, fishes, insects, mammals, mollusks, reptiles, and sharks. Explore special features on mammals, skulls, and frog calls. Students are invited to contribute.

How do you know if a chemical equation is balanced? What can you change to balance an equation? Play a game to test your ideas!

Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to:Define matter and elementsDescribe the interrelationship between protons, neutrons, and electronsCompare the ways in which electrons can be donated or shared between atomsExplain the ways in which naturally occurring elements combine to create molecules, cells, tissues, organ systems, and organisms

By the end of this section, you will be able to:Define matter and elementsDescribe the interrelationship between protons, neutrons, and electronsCompare the ways in which electrons can be donated or shared between atomsExplain the ways in which naturally occurring elements combine to create molecules, cells, tissues, organ systems, and organisms

By the end of this section, you will be able to:Identify and describe the properties of lifeDescribe the levels of organization among living thingsRecognize and interpret a phylogenetic treeList examples of different sub disciplines in biology

By the end of this section, you will be able to:Identify and describe the properties of lifeDescribe the levels of organization among living thingsRecognize and interpret a phylogenetic treeList examples of different sub disciplines in biology

Starting from atoms, see how many molecules you can build. Collect your molecules and see them in 3D!

Students learn about atoms and their structure (protons, electrons, neutrons) — the building blocks of matter. They see how scientific discoveries about atoms and molecules influence new technologies developed by engineers.

Working in teams of three, students perform quantitative observational experiments on the motion of LEGO MINDSTORMS(TM) NXT robotic vehicles powered by the stored potential energy of rubber bands. They experiment with different vehicle modifications (such as wheel type, payload, rubber band type and lubrication) and monitor the effects on vehicle performance. The main point of the activity, however, is for students to understand that through the manipulation of mechanics, a rubber band can be used in a rather non-traditional configuration to power a vehicle. In addition, this activity reinforces the idea that elastic energy can be stored as potential energy.

Students explore the science of microbial fuel cells (MFCs) by using a molecular modeling set to model the processes of photosynthesis and cellular respiration—building on the concept of MFCs that they learned in the associated lesson, “Photosynthesis and Cellular Respiration at the Atomic Level.” Students demonstrate the law of conservation of matter by counting atoms in the molecular modeling set. They also re-engineer a new molecular model from which to further gain an understanding of these concepts.

Students learn about the periodic table and how pervasive the elements are in our daily lives. After reviewing the table organization and facts about the first 20 elements, they play an element identification game. They also learn that engineers incorporate these elements into the design of new products and processes. Acting as computer and animation engineers, students creatively express their new knowledge by creating a superhero character based on of the elements they now know so well. They will then pair with another superhero and create a dynamic duo out of the two elements, which will represent a molecule.

Students conduct several simple lab activities to learn about the five fundamental load types that can act on structures: tension, compression, shear, bending and torsion. In this activity, students play the role of molecules in a beam that is subject to various loading schemes.

This course focuses on the fundamentals of structure, energetics, and bonding that underpin materials science. It is the introductory lecture class for sophomore students in Materials Science and Engineering, taken with 3.014 and 3.016 to create a unified introduction to the subject. Topics include: an introduction to thermodynamic functions and laws governing equilibrium properties, relating macroscopic behavior to atomistic and molecular models of materials; the role of electronic bonding in determining the energy, structure, and stability of materials; quantum mechanical descriptions of interacting electrons and atoms; materials phenomena, such as heat capacities, phase transformations, and multiphase equilibria to chemical reactions and magnetism; symmetry properties of molecules and solids; structure of complex, disordered, and amorphous materials; tensors and constraints on physical properties imposed by symmetry; and determination of structure through diffraction. Real-world applications include engineered alloys, electronic and magnetic materials, ionic and network solids, polymers, and biomaterials.
This course is a core subject in MIT's undergraduate Energy Studies Minor. This Institute-wide program complements the deep expertise obtained in any major with a broad understanding of the interlinked realms of science, technology, and social sciences as they relate to energy and associated environmental challenges.

In this classic hands-on activity, learners estimate the length of a molecule by floating a fatty acid (oleic acid) on water. This lab asks learners to record measurements and make calculations related to volume, diameter, area, and height. Learners also convert meters into nanometers. Includes teacher and student worksheets but lacks in depth procedure information. The author suggests educators search the web for more complete lab instructions.

Introduction to Solid State Chemistry is a first-year single-semester college course on the principles of chemistry. This unique and popular course satisfies MIT's general chemistry degree requirement, with an emphasis on solid-state materials and their application to engineering systems.
Course Format
This course has been designed for independent study. It provides everything you will need to understand the concepts covered in the course. The materials include:

A complete set of Lecture Videos by Prof. Sadoway.
Detailed Course Notes for most video sessions, plus readings in several suggested textbooks.
Homework problems with solution keys, to further develop your understanding.
For Further Study collections of links to supplemental online content.
Self-Assessment pages containing quiz and exam problems to assess your mastery, and Help Session Videos in which teaching assistants take you step-by-step through exam problem solutions.

About OCW Scholar
OCW Scholar courses are designed specifically for OCW’s single largest audience: independent learners. These courses are substantially more complete than typical OCW courses, and include new custom-created content as well as materials repurposed from previously published courses. Learn more about OCW Scholar.

This lesson explores the drag force on airplanes. The students will be introduced to the concept of conservation of energy and how it relates to drag. Students will explore the relationship between drag and the shape, speed and size of an object.