Properties of sodium, chlorine and sodium chlorides Chart Play

Rate of change in the exponential function Simulation Play

Rate of change in the function y = ln|x| Whiteboard exercise Play

Rate of change in the natural logarithmic function Simulation Play

Rate of change on the straight line Whiteboard exercise Play

Rate of change on the straight line Student activity Play

Rates of change Whiteboard presentation Play

Rates of change Class activity Play

Ratio of two quantities of different kinds Whiteboard exercise Play

Ratio of two quantities of different kinds Student activity Play

Ratio of two quantities of the same kind Simulation Play

Ratio of two quantities of the same kind Student activity Play

Reaction conditions and enthalpy change Slideshow Play

Reactions involving phase changes Animation Play

Reactions of complex ions Student activity Play

Reactions of complex ions Whiteboard exercise Play

Reading from graphs Student activity Play

Reading from graphs Whiteboard exercise Play

Recent changes in the Earth's temperature Slideshow Play

Recognising oxidising agents Student activity Play

Recognising oxidising agents Simulation Play

Recognising reducing agents Simulation Play

Recognising reducing agents Student activity Play

Recombination in bacteria Animation Play

Refraction of light Student activity Play