What happens inside a volcano - Volcano in a glass experiment

You could already tell from our first post that Teddy really likes volcanoes. Our paper mache one is starting to look a tad tired from all the erupting it has been through the last two months but Teddy just doesn't seem to have enough.

All that has sparked more questions and deepen his curiosity. Therefore I decided to spend more time on this topic bit further and we started to look at what happens inside the volcano. As an inspiration and a learning tool I used nomenclature cards, I downloaded from internet (I'm happy to share if you'd like just get in touch with me)

To make it more interactive I had an idea and made him a sort of a puzzle of the different parts out of felt. I always let Teddy to get involved in the process of making different activities and preparing everything for an experiment rather than presenting him with a done thing and I think its the fact that he helped me prepare it what makes it special for him.

He really liked the idea and didn't hesitate  to fetch his crayons and started to work on his design of a volcano which had a great amount of flowing lava. When he saw me cutting mine out he quickly went to get his own childrens scissors and started to cut his own. We had loads of fun just making this activity and he really likes the final product and is proud of himself that he knows where the lava comes from.

Those who follow us know that we really like experiments and that I believe that letting Teddy try it, see it and touch it helps a great deal in making him understand better.  Therefore I kept searching until I came across this really great experiment

Volcano in a glass experiment 

its called a volcano in a glass and instead of looking at what happens outside and all the flowing lava it focuses on what happens inside which was perfect. It looks at what happens to the mantle of the earth when it gets too hot pushing the magma through the crust of the earth

so if you'd like to try it this is what you need

• glass jar, cup or any other container which can withstand the heat (we used a glass jar we saved from pickled gherkins)
• wax (we used a red tea candle, because magma has to be red, doesn't it? I just removed the wick)
• clean sand (dirty works too, you just have to wait a bit longer for it to settle down)
• watersomething to hold the glass jar above the candle (we used cooling rack as you can see on the picture above)
• candle (or other source of heat but we found that candle works the best, if the heat is too strong the glass is most likely to shatter

How to do it:

Place your wax in the bottom of your jar, right in the middle of it

cover it with sand, pressing it nicely around the edges and  making sure its levelled (we did this experiment a few times and once we left a gap by mistake and it was actually cool to see the wax underneath the sand melting and bubbling before it risen to the top but make sure there is no gap on the top or it will rise before the magma is all nice and cooked!)

now fill the jar with a water all the way to the top, we used a spoon to hold the candle down. 

You might need to leave the sand to settle down, when we used clean sand it took 5 min, with dirtier sand a bit longer but it always settled! When the water is clear enough for you to see through place it on your cooling rack (or whatever you are using) and light up the candle and just wait for the magic to happen!

I have to say its not the fastest experiment, we actually missed the first explosion as we waited for some time and nothing happened so we got busy with other things. It takes around 10 min if you use a tea candle, if you use more wax it will obviously take bit longer. once we used 2x candles to have more magma and it took around 15 min to melt and and coming through.

What we do is to set it up together and then I let Teddy play and when the time gets closer we get back to watch. He loves to talk about what is going to happen and doesn't mind being patient for a bit, its worth it in the end!

Good sign to look for are the bubbles which will start coming through the sand shortly before the eruption happens. 

If you haven't already seen it, there is a longer video on our Facebook page: Mama and son time

The science behind it:

The wax in this experiment represents a layer in the Earth called the mantle, the mantle is solid but at a certain point it  becomes hot enough to melt, like the wax in the jar, it melts changing its density and rising rapidly towards the surface representing the magma (which is actually a molten rock from the mantle)

Both sand and the water are representing the crust of the Earth