Water beads are amazing crystals that absorb up to 400 times their weight in water and increase in size by. They will then shrink again as they loose water to the surrounding environment.
This makes them a fantastic visual material to show children absorption and expansion.
At this point I will mention that although they are non-toxic and biodegradable they are not a toy and are sold as not suitable for children. If you are going to use them do not leave your children unsupervised with them.
We measured the tiny crystal beads before they had water added to them and noted down the time, their approximate size and how much water we added.
Do go visit The Hangout page and take a look at all the other fabulous contributions for this weeks ‘Growing’ topic. There are some great activities mantioned.