Amazing water spheres!  Pop these 3.3 mm rock-hard spheres in water and within hours you will have 20 mm jelly-like spheres!  That's a 220 times increase in volume! They contain 95% water so the clear spheres will be invisible in water.  

Add food colouring to the water to get different coloured spheres or purchase the pre-coloured ones that are colour fast. Leave them out of the water and they return to the original hard spheres.  Then expand them again and again. Bounce, roll or squeeze them or germinate seeds amongst them. Loads of gelled fun!

Included: 20 grams of 3.3 mm spheres (~500 spheres).
See instructions & classroom tips under 'Downloads' on this website.

Teach: super absorbent polymers, gels, optical density, osmosis

Safety: Made from non-toxic super absorbent material, these spheres can't expand in the stomach's acidic environment but due to the small size are NOT classified AS TOYS.  We recommend adult supervision.

Age: 7+ with adult supervision. 

See our Expanding Cubes too.