A lazy, active volcano. 

I’m a lazy mum, honestly I am. I see so many interesting things to do but if it requires a shopping trip and more than 15 mins prep then it has lost me – it takes a lot of energy to clean bums whilst plastering an ever lasting smile on my face!!

The kids were watching an episode of ‘My Family’ on CBeebies on the other day and witnessed a family build a volcano – the whole shabang. Pva glue mixed with water, newspaper, dipping it all in, sticking it on, waiting for it to dry, paining it and then creating the magic.

My eldest turned it me with big bright brown eyes, an eager smile and said, “Can we do that mummy?”

My ever lasting smile started falling off my face. Ahhhhhh!! Noooooo! Please no! The mess! And I’ll be doing most of the work! But I kept calm and composed. “Yep, maybe we can.”

After doing a bit of research and thinking I was very happy to come across the idea of a ‘backyard volcano’ which literally was a volcano shaped out of a mound of dirt. No glue. No dripping mess. THIS we could do. So we did!

Now the kids had already seen a demonstration on television so they knew what was going to happen. Also, we’ve worked with vinegar and bicarbonate of soda (the ingredients needed to do this experiment) before – when we were looking at blowing up a balloon, which meant I had to think carefully about how to get some learning out of today’s activity.

So I decided that the following question was posed: Which would create the better/more explosive volcano – adding baking soda to vinegar? Or vinegar to baking soda?

I began the activity talking about volcanoes to see what they already knew. I then showed them a video about volcanoes which you can find here. We re-watched the CBeebies show and pointed out the ingredients they used to make the explosion. Had we used them before? My youngest was quick to say ‘egg!’ She picked up on the vinegar and remembered we had used it to make the bouncy egg – I was super impressed! I reminded them about the balloon experiment and with a little prompting they (well the eldest) remembered a few key words such as carbon dioxide. My youngest then went looking for the vinegar in the kitchen!! They remembered it looked like water and also did not fall for the ‘Mmmm, smell it’ trick!

I gathered the rest of the things needed. For this you will  need:
Bicarb of soda
Food colouring
2 containers/cups
A jug & spoon

Whilst the kids were busy putting their shoes on I poured the vinegar into the jug and mixed in the food colouring (a large amount!)

Off we headed into the back garden. We have lots of gravel/stones in our garden in certain areas – it was with this we created a ‘mound’. You can do it with sand, soil/mud if you prefer or have that to hand instead. If none of these are available then do not worry! You could do this whole experiment with 2 cored apples!! By removing the core of the apple, you have your ‘container’. Just make sure they are the same type of apples because different types of apples can effect the result – but that’s a whole other experiment. When doing science its best to change one variable at a time – so keep it fair and simple.

In the top of the mound the cup was placed and pushed down. We created two volcanoes as we would be comparing the explosions created by changing when an active ingredient would be added.

In one volcano we added bicarb of soda to the cup. In the other we added the vinegar.

Now the preparation was fully complete it was time to make predictions. Which would create the more explosive volcano – adding vinegar to baking soda? Or adding baking soda to vinegar?

Each volcano was tested individually and here are the results…..

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The kids LOVED this. So did I – and no mess to clean up (well apart from washing the pots and jug – but when is there not washing up??). The stones were flattened out and the rain will wash away the rest.

The science bit:

The vinegar (acid) and bicarb of soda (base) mix to make an acid-base reaction, producing carbonic acid. This product is very unstable and splits to form water and carbon dioxide which expands and rises up. Having the vinegar poured directly onto the soda (so putting the soda in the cup first) means that the vinegar makes contact with as much soda as possible and so produces a ‘better’ result than adding the bicarb to the vinegar.

Bicarbonate of soda
Carbon dioxide

Key questions
What do you know about volcanoes?
What colour is lava?
What happens when you mix vinegar and bicarbonate of soda?
What is the gas that is made?/Why are there bubbles?
Which will make the bigger/better explosion?

Simple, cheap, quick and explosive fun…..ENJOY!


Then I’ll huff, I’ll puff and I’ll blow that balloon up!

Today’s investigation all started from a conversation about a bowl of cereal, would you believe it!
Whilst eating a bowl of Rice Krispies we talked about what it actually was, that they were eating and how it was made. Big kid likened it to pop corn and then, blowing a balloon. Thumbs up from me!

I love how they make the links. The kids, well, they just love balloons (and cake). We have a lot of them (balloons, not cake). They love balloons – have I mentioned that before? So I directed the conversation to asking them if they would like to find out how to blow a balloon without using their mouth.

Cue excited faces.

Still in our Pj’s, I pulled some bits out of the kitchen and we began. I enlisted the other half’s help for this so that I could capture the action. This activity required *very* little and takes even *less* time.

We began with some focusing on the actual action of blowing and getting them to think about what they were doing and where it was coming from before trying to blow a balloon.

They huff and they puffed…..before the big bad wolf stepped in to show them how it was done.

I introduced the term carbon dioxide, yes, despite their age. Hey, if they can say Tyrannsaurus Rex then they can learn to say carbon dioxide!! Even the little one gave it a fair go – it was incredibly cute….car oxide was managed!

I will add here that in the past the older one and I have talked about plants taking in ‘bad air’ and giving us the ‘good air’ (he once asked what the plants and grass was for and why there were around). I was able to make the link here between the ‘bad air’ and carbon dioxide. I mentioned it was a gas but refrained from linking this to a fart- well, the other half did with a very firm look from myself.

With no further ado we proceeded with the experiment. For this you need:DSC_0082

  • Vinegar (white vinegar is better but we had malt vinegar and it worked just fine)
  • Bicarbonate of soda
  • Plastic bottle (75cl)
  • A straw
  • A balloon
  • A spoon, for just in case.

The first thing to do was to fill the balloon with around 2 tbsps of the bicarb of soda. Ideally, a funnel would be best to use to do this – but this would need two people (one to hold the balloon open and another to fill it). We did not have a funnel and so used straw instead.

Next the plastic bottle was filled with around 2-2.5cm of vinegar. Then the last step was to stretch the balloon over the top of the bottle, allow the contents to hit the vinegar and watch the magic happen! Just make sure you hold the base of the balloon down on the bottle throughout.

They loved it! And it really did not take very long either, the chemical reaction begins immediately. The vinegar and bicarb mix to make an acid-base reaction, producing carbon dioxide which expands, rises up and inflates the balloon.

There are lots of factors you can investigate with this experiment to take it one step further and develop the learning. You can have a go with different balloon sizes, bottle sizes and even different amounts of vinegar and bicarb of soda – but not all at once if you want to draw valuable conclusions.


Give this a go, it is so quick and simple!

And next time an offspring runs up to you with a sopping wet balloon due to repeated attempts at inflating it…..point them to the kitchen!


  • Blow
  • Lungs
  • Air
  • Gas
  • Carbon dioxide
  • Vinegar
  • Bicarbonate of soda
  • Acid
  • Mixture
  • Bubbles

Key questions:

  • Can you blow out air?
  • Where in your body can you feel it (air) coming from?
  • What can you see happening?
  • Did it blow it up as big as person could?
  • What could we have done to blow the balloon up bigger?
  • What was better at blowing up a big balloon?
  • Why could you not blow up the balloon as big as mummy/daddy?


Clearly the spoon came in handy…..!