As it’s nearly Bonfire night in the UK we thought was should do a firework experiment. A firework in a jar is totally safe, very easy and looks just like a firework without the bang and sparkle.
These also make a great science activity for New Year.
What you need to make a firework in a jar
A tall jar
Warm water
Oil
Food colouring
How to make a firework in a jar
- Fill the jar about ¾ full of warm water and then add a layer of oil.
- Carefully drop the food colouring into the oil.
- Watch what happens.
Why does it work?
Oil and water do not mix! Also oil is less dense than water (meaning there is less of it in the same volume) and therefore floats on top of water in a nice layer.
The food colouring we used was water based and therefore does not mix with the oil, instead it sinks through the oil into the water below.
Food colouring is more dense than water and so sinks to the bottom of the jar leaving trails (resembling fireworks) as some of the colour diffuses into the water.
We noticed that some blobs of food colouring sank to the bottom and then after a few moments shot up (resembling a more conventional firework) – Why do you think this might have happened?*
*We think this might be because an oil droplet was trapped inside a food colouring droplet and sank, but as the edges of the food colouring droplet diffused into the water suddenly the drop became less dense than the surrounding water (thanks to the less dense oil at the centre) and floated upwards quickly…
Last Updated on January 24, 2023 by Emma Vanstone
ChocOrangeCityMum
This looks like great fun for small kids, will try it with my Boy.
Thanks!
Sarah
This is fun with BIG KIDS – a definite hit with 11-13 year olds in science club
Multiple Mummy
Very cool! Love this! x
Rashmie @MommyLabs
Emma,
What a coincidence! We too enjoyed a similar experiment in bottles. We added fizz tablets that cause really firework-like reactions. Just linked it up above.
Smallgood
The video was great! I had never seen this done before.
Brooke @let kids create
So cool, I love the second blast that comes up at the end. I’ve got to do this with my girls.
ScienceSparks
Oooh let us know how you get on. xx
Beth
Very cute idea! We are going to have to try that. I wanted to invite you to come link up at TGIF Linky Party – http://livinglifeintentionally.blogspot.com/search/label/Linkey%20Parties & I’ll link up too!
Beth =-)
ScienceSparks
oh yes, of course. I will check it out now. xx
Almost Unschoolers
Bonfire night? I have to go look that one up! 🙂
Almost Unschoolers
…aw, Guy Fawke’s Night! My husband is actually descended from Tresham’s who came to the US after their relatives failed involvement with the Gunpowder plot – maybe we should light a bonfire too 🙂
ScienceSparks
oooh really? How interesting. You should join in the celebrations. xx
Liberty
This is wonderful!!! I cannot wait to do this with my little one. Your site is amazing – Thank You!!!
ScienceSparks
I’m so glad you like is, thank you. xx
Carrie
This site is great! My son loves science, and I am always looking for ways to foster that! Pinned, and your newest GFC follower!
ScienceSparks
I’m so glad you like us, thank you. xx
maggy,red ted art
Wow! Looks absolutely fabulous! Don’t you just LOVE SCIENCE 🙂
Thank you for sharing on Kids Get Crafty!!
Maggy
creativejewishmom/sara
looks great, love all your experiments and you’re filling such an important little spot in our party that was empty until you came along! thanks so much for stopping by regularly to share on Craft Schooling Sunday, i really appreciate it!
Mom to 2 Posh Lil Divas
so cool – will be doing this at some point for sure!
Thanks for linking to the Sunday Showcase! Can’t wait to see what you share with us this week.
Bern
http://momto2poshlildivas.blogspot.com/search/label/Sunday%20Showcase
ScienceSparks
So glad you liked it! x
Hot Cross Mum
Cool – love this little experiment!