We see animations of atoms that explain collision theory. Animations are also used to show how increasing temperature, concentration and surface area, and adding catalysts to reactions, can increase the rate of collision.

First broadcast:
21 November 2008

This clip could be used to introduce students to factors that influence rates of reaction. Following the clip, students could undertake experiments to measure the effects of temperature on rate of reaction. For example, by dissolving an indigestion tablet in hot water, water of room temperature and cold water (with ice) students could measure rates of reaction. They could then add lines to a pre-drawn graph to show the differences in the rate and the end point of reaction when the temperature of the water has changed.
For more in-depth investigation they could look into how changes in concentration, temperature and surface area affect the speed of reaction when sodium thiosulphate and hydrochloric acid are mixed together.