What determines the concentration of a solution? Learn about the relationships between moles, liters, and molarity by adjusting the amount of solute and solution volume. Change solutes to compare different chemical compounds in water.

You probably remember the mole from high school chemistry, but do you remember why it is useful to chemists? The goal of the following video is to give the "big picture" of the mole and its applications; information on how to use the mole in calculations can be found in another tutorial. Throughout this course, we will use the term "molecular weight" to refer to the mass of a mole of a substance (for instance, the molecular weight of oxygen (O2) is 32 g/mol). Recent textbooks refer to this as "molar mass" to emphasize (i) that this term refers to the mass, not the weight, of substance, and (ii) that the quantity refers to a mole of a substance, not a single molecule. "Molecular weight" may be less precise, but it remains the term that most practicing chemists use in the laboratory. For this reason, we continue to use "molecular weight" in this course.

This lesson is an introduction to the history and use of the scientific concept of the mole.

Small molecules are chemicals that can interact with proteins to affect their functions. Learn about the structure and biological functions of various small molecules like sugar and caffeine. Also featured on the HHMI DVD, Scanning Life's Matrix: Genes, Proteins, and Small Molecules. Available free from HHMI.

Discover what controls how fast tiny molecular motors in our body pull through a single strand of DNA. How hard can the motor pull in a tug of war with the optical tweezers? Discover what helps it pull harder. Do all molecular motors behave the same?

In this activity, students interact with 12 models to observe emergent phenomena as molecules assemble themselves. Investigate the factors that are important to self-assembly, including shape and polarity. Try to assemble a monolayer by "pushing" the molecules to the substrate (it's not easy!). Rotate complex molecules to view their structure. Finally, create your own nanostructures by selecting molecules, adding charges to them, and observing the results of self-assembly.

In this interactive activity from ChemThink, learn about covalent molecules and how the VSEPR theory predicts the shapes of covalently-bonded molecules.

This module is an introduction to using VSEPR to predict molecular shape based on Lewis structures.  It is limited to steric numbers of 6 or less.

This chemistry activity was created to enhance student learning about molecular structure. It guides students through Phet simulations and then asks comprehension questions thereafter.

Created by the Concord Consortium, the Molecular Workbench is "a modeling tool for designing and conducting computational experiments across science." First-time visitors can check out one of the Featured Simulations to get started. The homepage contains a number of curriculum modules which deal with chemical bonding, semiconductors, and diffusion. Visitors can learn how to create their own simulations via the online manual, which is available here as well. The Articles area is quite helpful, as it contains full-text pieces on nanoscience education, quantum chemistry, and a primer on how transistors work. A good way to look over all of the offerings here is to click on the Showcase area. Here visitors can view the Featured simulations, or look through one of five topical sections, which include Biotech and Nanotechnology. Visitors will need to install the free Molecular Workbench software, which is available for Windows, Linux, and Mac.

This course is a reading supplement to Cells: Molecules and Mechanism by E.V. Wong

Join our team of young explorers on their mission to save nature from pollution! When this group of friends discovers the impact people have on their environment, they embark on a quest for justice and answers that quickly throws them into a whirlwind of adventures. Their goal: to find powerful molecules capable of solving the pollution problem. Get ready for an exciting journey through unexplored territories and discover the microscopic power hidden all around us. Be part of our quest for a greener world!

This package, written in 1998, includes interactive questions and demonstrations on the dynamics of chemical reactions. The aim is to show the effect of the potential energy surface, on reaction rates.

It is intended for third or fourth year undergraduates in Chemistry.

To download, click on View Download and follow the instructions. To uninstall, use the standard Windows option of “Add or Remove Programs”.

Students will predict bond polarity using electron negativity values; indicate polarity with a polar arrow or partial charges; rank bonds in order of polarity; and predict molecular polarity using bond polarity and molecular shape.

Explore molecule shapes by building molecules in 3D! How does molecule shape change with different numbers of bonds and electron pairs? Find out by adding single, double or triple bonds and lone pairs to the central atom. Then, compare the model to real molecules!

Explore molecule shapes by building molecules in 3D! Find out how a molecule's shape changes as you add atoms to a molecule.

A fun lab experience with little extra prep or materials needed. Kids are amazed that 1+1 doesn't equal 2!

Students work as engineers to learn about the properties of molecules and how they move in 3D space through the use of LEGO MINDSTORMS(TM) NXT robotics. They design and build molecular models and use different robotic sensors to control the movement of the molecular simulations. Students learn about the size of atoms, Newman projections, and the relationship of energy and strain on atoms. This unique modular modeling activity is especially helpful in providing students with a spatial and tactile understanding of how molecules behave.

Do you ever wonder how a greenhouse gas affects the climate, or why the ozone layer is important? Use the sim to explore how light interacts with molecules in our atmosphere.

In this two-part activity, learners use everyday materials to visualize one mole of gas or 22.4 liters of gas. The first activity involves sublimating dry ice in large garbage bag. The second activity uses plastic bottles.