Emma from the lovely Science Sparks sent us this absorbing experiment looking at materials and how they soak up!

Investigating Sponges

This investigation looks at why sponges are so good at absorbing water. It is very simple to do, but can be a bit messy so I wouldn’t do it on the carpet!

What you need:

  • A bowl or tub of water
  • Absorbant materials, such as sponges and wash cloths.
  • Non absorbant materials, such as plastic blocks or pencils.


  • Place the sponge in the water first to demonstrate how it absorbs the water. Does a dry sponge absorb better than a wet sponge? Can you hold the wet sponge up in the air without the water escaping?
  • Try the washcloth and show how it does absorb some water, but cannot retain most of it.
  • Place the plastic blocks and other non absorbant materials in the water and see what happens.

The Science Bit

Sponges are made of loose fibers with lots of space between them. The holes between the sponge fibers absorb the water, and so the sponge material swells up with water. This stops the water coming out of the sponge when you lift it out of the water. When you squeeze the sponge you are forcing the water out of the holes in the sponge.

A wet sponge will absorb more water than a dry sponge as water molecules are highly attracted to one another.

Thanks Emma! More from Science Sparks Next Month!

Don’t forget we have some great Science kits for children at GLTC:

Primary Science Kit – £30

An easy to follow, educational set which introduces simple but key scientific concepts to children – such as the growth and nutrition of plants and what makes things float.

Features: Experiments include Mini Volcano, Colour Changing Celery, Dancing Raisins, Mixing Impossible, Sink and Float, What’s That Smell, Seeds and Sprouts, Investigating insects, Shiny Pennies, Colour Mixing.

Set Includes: Flask, beaker, goggles, eyedropper, tweezers, magnifying glass, funnel, 2 small test tubes with lids and stand, large test tube with lid and stand, 10 activity cards with easy to follow experiments.

Explorer’s Set – £7

Encourage your child’s interest in science and nature with these perfectly sized tools – the big tweezers are great for developing fin motor skills too.

The magnifier features: a built-in stand for hands-free observation, clear 4.5x magnification and 11cm diameter viewing area.

Tweezers feature: easy-grip depressions for proper pincer positioning and measure 15cmL.

Choose from: Red/Blue or Yellow/Green.

Happy Experimenting!