American Chemical Society
Exothermic, Endothermic, and Chemical Change
Scientists can't observe bonds breaking or forming, so how do they distinguish between exothermic and endothermic reactions? Young scholars complete two experiments to do just that. They monitor temperature change and calculate the...
American Chemical Society
Energy and Entropy of a Stretched Rubber Band
Stephen Perry invented and patented the modern rubber band in 1845. Young scientists put his discovery to work as they use rubber bands to observe entropy and enthalpy. They determine the change in free energy to figure out if it...