Determine the number of possible genetic codes. Class members are challenged to determine the number of possibilities of a genetic code that is 20 bases long. They continue to explore the average lengths of broken RNA molecules.

In this chemistry learning exercise, test takers answer 60 multiple choice questions on topics related to chemistry from balancing equations to calculating moles and molecules of compounds. They name formulas, they convert, they solve...

Sixty multiple choice questions cover the entire gamut of chemistry concepts. This is the local section of the U.S. National Chemistry Olympiad, where your chemistry candidates take a shot at entering the national competition. They...

A variety of topics including reaction rates, combustion reactions, periodic trends, and ionization reactions are included in this exam. Test takers also practice calculating empirical and molecular formulas of compounds.

This is an online exercise in which chemistry learners answer a series of multiple choice questions about bonding. Topics addressed include ionic and covalent bonds, electronegativity, ions, valence electrons, resonance structure, and...

The liquids did not mix — so what do density columns have to do with it? The seventh part in a series of nine provides the theoretical explanation of why density columns do not mix. The lesson plan covers the topics related to...

I can move about freely, but you cannot. The class models the movement through cell membranes by way of passive and active transport. Members of the class play the roles of various proteins, atoms, compounds, and cell actions and mimic...

Discover what you know about the nature of molecules by taking this pre test.

This simulation explores the relationship between mass, moles, molecules and atoms. Select one of the 6 compounds, set the mass of the compound, and release the scrollbar to calculate.

Take an interactive quiz over the molecules of life. After completing the quiz, check your score, and then revisit any incorrect question for further review.

Take this interactive, multiple-choice quiz over the organic molecules important to life, then review your score and any missed questions at the end.

Practice questions over regulating electron carrier molecules.

Discover what you know about the nature of molecules by taking this post test.

Watch a short tutorial showing the conversion between the amount of a substance expressed in number of molecules to the amount of a substance expressed in moles of molecules, and then try some dimensional analysis practice problems.

Two multiple-choice quizzes, one on the processes and types of biological molecules, the other on the structure and replication of DNA.

Take this interactive, multiple-choice quiz over the molecule of life, DNA. Then review your score and any missed questions at the end.

This is a five-questions quiz related to the principles of bioenergetics and fuel molecule metabolism.

Quiz yourself with questions related to the principles of bioenergetics and fuel molecule metabolism.

In this exercise students will select the electron-pair geometry for a molecule and drag it onto the central atom. Then they will place the terminal atoms in the appropriate positions on the molecule. Finally students will enter the...

This program asks students to determine the average KE of a gas molecule in a sample and then find the temperature of the particles that make up the sample based on the rms speed of the particles.

This program asks students to determine the average KE of a gas molecule in a sample and then find the rms speed of the particles that make up the sample.

A set of interactive stereochemistry review problems. Requires Chime plug-in.

Try these twenty multiple-choice questions to review the concepts of the chemistry embedded in biology. Each question has a clickable hint, and the entire assessment is self-checking.

Try these five multiple-choice questions about the building blocks of life. The quiz is self-checking, and provides hints to the student if needed.