There are three versions of this diffusion question.  We recommend using two versions of the questions above to compare student responses to different molecules.

We recommend that you administer these questions as homework and preface the question with these instructions for students:

"For the following question, please respond to the best of your knowledge and using only the information in the question and what you know. Please do not refer to any outside sources (textbooks, notes, internet, etc.). Any reasonable attempt to answer the question will be awarded full credit."