It has taken many attempts to get these crystals to grow. The first time we tried nothing grew at all as the solution was not concentrated enough, the second time we made it too concentrated and the whole solution crystallised. The third time we grew this, and were quite impressed!
Photo taken with this.
What you need
3 cups of caster sugar
1 cup of water
A lolly stick or circle of wire. Or some string.
Some sparkles and/or food colouring( optional )
Dissolve the sugar in the water, as soon as it is dissolved remove the heat and leave to cool a little bit. If you can get a bit more sugar to dissolve then thats a good thing. We want a saturated solution.
Pour the solution into a glass jar and suspend the lolly stick, we used some sellotape to hold it in place. Don’t let it touch the bottom or the sides. Alternatively you could tie some string to a pencil and rest the pencil on top of the jar with the string hanging in the jar.
You should see crystals start to form after a few days.
We made a lolly and a circle to hang on the Christmas tree. I was a bit disapppointed with the circle, but we will be trying again with a star!
The Science Bit
A crystal is a solid material with a naturally geometrically regular form. Some take millions of years to form, such as diamonds. The crystals we made above take just a few days.
Most minerals dissolved in water will form crystals given enough time and space. The shape of the crystal formed depends on the mineral’s molecule shape.
In the case of our sugar crystals there are two process at work.
Evaporation – the water evaporates slowly meaning the solution becomes more saturated, so the sugar molecules come out of solution and collect on the string/wire or stick.
Precipitation – the solution we made was very concentrated which means there was too much solute to remain dissolved in the water, therefore it starts to precipitate.
I added some pink sparkle and some peppermint flavouring to the lollypop to make it a bit Christmassy!
If you take any videos or photos of you and your children doing any of our activities please share on G+ and tag us using #ScienceSparks. I’d love to see and share them around.