Last week I left you without the spring theme that we promised you to bring every Wednesday from the beginning of the season, however there is little to start the summer and I want to share with you two articles that can go very well in any of the two seasons Hotter
Today we will see through an experiment (which you will then do at home with the children) as the water expands when it freezes. It turns out that all liquids change in density with temperature: they become less dense at more temperature, but the water is very peculiar because it increases the volume when it freezes (and decreases the density), so the opposite occurs than with the rest of liquids . Water takes more place when it freezes, because their molecules unite forming a different structure (in the form of hexagons). And if it is interesting for children to observe the three states in which it can occur, it is also interesting to verify that they can measure their volume in a simple way.
So how will we do it?
Necessary materials: water, a little food coloring or concentrated sweet syrup, a sipping stick, a permanent black or blue marker, a plasticine ball and a plate.
Let's start our experiment
You will see how it is very simple: first we will mix the water (with half a glass there is enough) with the dye; then we must sip with the cane a little of the mixture (without swallowing, although nothing would happen if they ingest a little unintentionally). When we separate the cane from the glass, we must cover the lower end with a finger and immediately seal it with a little plasticine.
Now we will form a ball the size of a nut with the rest of plasticine and place it on the plate, to embed the part of the cane that we have not covered there (normally the water does not spill because it closes at both ends). Finally we have to mark the water level with the marker on the cane and put everything in the freezer.
When we go to see our experiment, we will see how the volume of tinted water (now solid) has increased, and we will know it because it exceeds the mark we have painted.
Do you dare? Surely now you have more free time (with the continuous day of children in June), and also want this type of tests with water, right?
And next week we will finish with the series that we started talking about planning and equipment for mountain excursions with children, and we will do it with some fun reading points that you can do at home.
