Plasma: the fourth state of matter Student activity Play

Precipitation of insoluble salts Animation Play

Precipitation of silver halides Student activity Play

Pumping an (inner) tube Whiteboard exercise Play

Purity test Animation Play

Radiation and a charge Animation Play

Reaction between metals and acids Student activity Play

Reaction of concentrated sulphuric(VI) acid with copper Whiteboard exercise Play

Reaction of potassium bromide and potassium iodide with sulphuric acid Animation Play

Reactions between Group 1 and 2 metals and water Student activity Play

Reactions between metal halides and concentrated sulphuric acid Student activity Play

Reactions of complex ions Student activity Play

Reactions of complex ions Whiteboard exercise Play

Resonance Student activity Play

Resonance in technology Slideshow Play

Reversible and irreversible reactions Student activity Play

Roentgen's experiment Animation Play

Root hair Whiteboard exercise Play

Root hairs Student activity Play

Roots Student activity Play

Solubility of salts Student activity Play

Solubility of silver halides Whiteboard exercise Play

Stratified sampling Student activity Play

Structure of a starfish – a typical echinoderm Slideshow Play

Structure of the ear Animation Play