Magic sand is magic because when it is in water, it stays dry. Observe and learn about the usefulness of this hydrophobic substance
The chemistry involved in this activity can be used in all kinds of ways, from children’s toys to cleaning substances.
Children will develop their working scientifically skills by:
- Using appropriate scientific language and ideas to explain, evaluate and communicate their methods and findings.
- Drawing conclusions and raising further questions that could be investigated, based on their data and observations.
- Asking their own questions about scientific phenomena.
- Compare and group together everyday materials on the basis of their properties.
Children will learn:
- That the properties of different materials determine how suitable they are for different purposes.
What to do
Pour some of the magic sand into a container filled with water. Watch what happens to the sand.
- Put your hand into the container and play with the sand, what does it feel like?
- Try and lift some of the sand out of the water, what do you notice when the sand is above the water?
- If you don’t want to get wet put some Magic Sand on a petri dish or plate and place a drop of water on the sand, what do you notice?
What’s the chemistry?
Magic sand is magic because even when it is underwater, it stays dry! When ordinary sand gets wet it sticks together, forming clumps, but magic sand is different. It starts out as normal sand but is then coated with a substance that keeps water away, this sort of substance is called a hydrophobic substance.
The coating on magic sand is similar to some types of cleaning products, which are sprayed on fabrics to protect them from stains.
Suggested activity use
This activity could be used in a number of ways, depending on the ease of access to ‘magic sand’. You could use the activity with small focus groups to stimulate discussion and questioning between learners. It could be used as a demonstration to get children thinking about any real-life applications of the sand. Alternatively, learners could work in groups to test the sand and ask questions about what they are observing.
Children may need an explanation about what the term ‘hydrophobic’ means and how the sand works, before being able to suggest viable real-life applications.
Magic sand will need to be sourced prior to the activity. It would also be good to have samples of ordinary sand to compare it with.
- Handout | PDF, Size 4.38 mb
These resources were created for the Cambridge science festival 2014.