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Does it always sink?

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Children all explore for themselves the ‘concepts’ of float and sink just about every night in the bath.

And I’ve found we can make the experience even richer, by adding various things from around the house to the bath toys.

A large plastic ball that floats, for example, plus 2 small plastic balls of the same size, 1 that sinks and 1 that floats, allows children to see that whether something floats or sinks is a complicated combination of size and weight.

Float or Sink Concepts

This early self-exploration is a great foundation for asking lots more questions:

  1. Does size make a difference?
  2. Does what things are made of make a difference?
  3. Does weight make a difference?
  4. Does something that sinks in water sink in all liquids?
  5. Can you change whether or not something sinks in water?
  6. If you hold something under water will it float when you let go?
  7. What different things float in different liquids?
  8. Do some things float with more air in them?
  9. Can you continuously change whether something floats or sinks?
  10. Do frozen things float? What happens when they melt?

Luckily there’s loads of fun, simple experiments – not all of them bathtime friendly! – that you can do, even with pre-schoolers, that allow children to explore these questions for themselves.

The key thing I’ve found is that it doesn’t matter if you ‘know’ the ‘right’ words to explain what’s going on – my science education sucked, so I certainly don’t.  

Just have the confidence to ask questions and to help children observe what happens – that’s science!

Float or Sink Experiments

We’ve already enjoyed some of these fab ideas for experiments from our fave bloggers and can’t wait to try the rest …

  1. A simple does it float or sink tray Hands On As We Grow and Trial and Error Mama
  2. An outdoor float and sink tray including wood that floats and duplo that floats until it’s full of water from Fresh Art Photography
  3. An outdoor version of a float or sink tray Take Time for Today
  4. A sink or float bottle from Familylicious
  5. Seeing what happens to a balloon when you put more air in it Teach Pre-school
  6. Making pop corn dance in fizzy water Kids Activities Blog and making raisins dance in fizzy water from Mom To 2 Posh Lil Divas
  7. Making something heavy float in water Kids Activities Blog and Sugar Snips
  8. What do you need to do to a lemon to make it sink Science Sparks
  9. Floating ice and making rainbows 5 Orange Potatoes
  10. Shakeable density jars from A Homemaking Journey showing coloured oil and water separating, silt settling, glitter falling and lots more ..,
  11. What do you have to do to make a marshmallow sink Steve Spangler
  12. Why do diet soda cans float but full soda cans sink Yo Mamma 321 (you need to scan right down the post for this experiment)
  13. The impact of water temperature on food colouring dispersal Raising Sparks
  14. Exploring colour dispersal in water with different amounts of salt in Inspiration Laboratories
  15. Combining different things to make something “flink” 🙂 Lets Get Fancy
  16. A very simple density jar showing different things floating different liquids Science Sparks
  17. Multi-layered density jars from I Love Charts and Science Sparks
  18. Making eggs float in water by adding salt from Experimenting Mom and Tinker

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Float or sink? ... Loads of fun science experiments for kids to help them explore why objects float or sink #STEM #Science #KidsActivity

Ali Gilbert

Saturday 8th of August 2015

Great list! Thanks for sharing on #ToddlerFunFriday!


Tuesday 12th of February 2013

What a great collection of ideas! Lots of ways to make science more fun.

Thanks for sharing at Sharing Saturday.

Mums make lists

Thursday 14th of February 2013

We're having so much fun with them - can really recommend - Alice

Hannah White

Tuesday 12th of February 2013

Great experiment and great questions to encourage thinking! Thanks so much for sharing this with us at Eco-Kids Tuesday! Please come link up with us again today!

Mums make lists

Thursday 14th of February 2013

We'll be there - Alice x

Trisha @ Inspiration Laboratories

Tuesday 12th of February 2013

This is a great list! We love exploring density. We'll have to check out all of the activities.

Mums make lists

Tuesday 12th of February 2013

Writing the list really opened my eyes as to just how much we could explore - I am learning so much myself :-)

Cerys Parker

Monday 11th of February 2013

These look fantastic it's something that we haven't done any of at home at all.

Thank you for linking up to Tuesday Tots and just to let you know that I will be featuring this post this week on Rainy Day Mum

Mums make lists

Tuesday 12th of February 2013

We're having a lot of fun with them here - thanks so for much for featuring Cerys x