You will need:
✅ Two large, strong ziplock bags OR two plastic tubs with secure fitting lids, one must fit inside the other with plenty of spare space.
✅ 150ml carton of cream
✅ Vanilla extract
✅ 3 tsp of caster sugar
✅ Plenty of ice
✅ 6 tblsp of salt
✅ Wooly gloves
1. Put the cream, sugar and vanilla into your first bag (or the small plastic tub). Seal it well. Make sure there are no leaks.
2. Place the ice in the second bag (or large plastic box) and then place the first bag or box inside too.
3. Quickly check that your bag (or box) will close properly before going further. If not, take out a little ice.
4. Now add the salt to the bag /box of ice. Seal it up well.
5. Now put on your gloves and get shaking. Shake shake shake! You will need to shake for about 15 minutes. I can heartily recommend putting on some music for this bit.
6. The ice cream should be frozen, and the outer bag should be full of mostly melted salty ice.
7. Carefully remove the inner bag and enjoy your ice cream!
The Science at Work
Adding salt to pure water changes its MELTING POINT. Salty water melts at a lower temperature than pure water. This means that when we add salt to the ice, it starts melting very quickly.
As the ice melts, it needs to take in energy to do so. This is because, in the solid ice, the particles are vibrating on the spot. In a liquid, like water, they move around slowly. They need some energy to get moving and become a liquid.
In this experiment, the salty ice takes energy out of the cream in order to melt. This causes the cream to freeze.
Key Points
KS2
- The terms solid, liquid and gas.
- How solids, liquids and gasses behave in simple terms.
- Look at examples of melting, freezing, evaporation and condensation.
KS3
- Focus on what is happening to the particles during changes of state. They should be able to draw simple diagrams to show the particles in solids, liquids and gasses, and describe how these particles move.
KS4
- Focus on how the ammount of energy a particle has affects the way it behaves. I.e. the more energy a particle has, the faster it moves and it will spread further apart from the other particles.
KS4
- Link this to how higher temperatures can be used to speed up chemical reactions. Reactions happen when particles collide. Particles that are moving faster will collide harder and more often.
Suggested Extension
Find out about Roman Ice Cream. They didn't use plastic bags, but other than that the process is the same. They put some strange flavourings in! This site is a great starting point. digventures.com/2015/06/recipe…
Why do we salt the roads in winter?
Ask this question. See if your child can apply what we just learned about salt, water and melting points to explain why this works.
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I heard in the ether that there was a Facebook group called "Christans Against Dinosaurs". So, I searched for it out of morbid curiosity. Please join me on a tour of the oryctodromeus hole I fell down. First, what I understand is the OG group.🧵 1/15
In response to the Christian threat the Dinosaurs have formed their own Facebook Group. Apparently the Dinosaurs outnumber the Christians 4:1. I am concerned that there may not be enough Christians to feed all the Dinosaurs. Hopefully, most of them are herbivores. 2/15
The Battle Royale is now in progress! Move over lions. The Christians have a new adversary entering the arena! The Raptor Resistance. 3/15
This has reminded me of a tale, passed down through three generations of my family, about a weapons test that went humorously wrong. (Although not as spectacularly as the Panjandrum.)
My Grandfather Graham Lee was one of the scientists working on the Bouncing Bomb with Barnes Wallis (whatever the film might suggest, Wallis didn't do it all himself). He was a chemist specialising in explosives and furzes.
Here he is with my Grandma, Dad and Auntie Ann.
During the time when they were testing & training at Ladybower Reservoir in Derbyshire, they had to ensure each dummy bomb was confirmed at the bottom of the reservoir or recovered at dawn. This was to ensure enemy espionage did not get wind of the design or the plan of attack.
As we once more restrict our movement to help save lives, here is a reminder of the deities in the Idol Scribblings pantheon who can help us get through this.
A worshipper of Sloth can flick through all 999 television channels like a Catholic prays their way around the rosary. idolscribblings.blog/2020/03/29/slo…
If you would prefer your Wine Marten with white text for a dark coloured garment (which will hide the splashes of Claret), click here... redbubble.com/shop/ap/579541…
(I am always impressed that Buttercup pushes The Man in Black off Carl Wark so hard that he lands nine miles away in Cave Dale. That's a good angry shove you've got there girl.)
Anyway back to the holiday.
Played a bit of Historic Graveyard Bingo in Castleton.
I scored for, "The stonemason accidentally ran out of space".