In this final “Ask the Experts” column, our own resident “expert” and Department Editor, Marc Rosner, addresses the following questions:

• Why is chocolate bad for dogs?
• Where does the color go when paper fades after sun exposure?
• How do you measure weight in space?
• Since “at risk” students often have difficulty with traditional academic work, it seems they should benefit from exploratory, constructivist activities. In practice, when teachers implement inquiry-type activities, controlling such classes in the requisite atmosphere of freedom can be a challenge. What advice do you have for teachers who wish to implement modern pedagogy with students not used to the new boundaries?
• What makes one element a better conductor than another?