KENNETH EWARD / BIOGRAFX / SCIENCE PHOTO LIBRARY KENNETH EWARD / BIOGRAFX / SCIENCE PHOTO LIBRARY
LIBRARY Chemical reaction. A computer-generated model showing a chemical reaction. A chemical reaction occurs when one or more elements or compounds (the reactants) form new compounds (the products), by breaking or forming chemical bonds. Strong forces of attraction hold atoms together in a molecule or a crystal, a typical chemical bond has an energy of 500 to 1000 kJ/mol. This is the amount of energy required to break the bond. This image shows a change in the bond between the atoms represented by the yellow and the dark blue.
Model release not required. Property release not required.