Sensory floating and sinking bottles

Challenge the children to investigate these sensory floating and sinking bottles.

Early Learning Goal links

  • Mathematics ELG: Numerical Patterns
  • Understanding the World ELG: Past and Present
  • Understanding the World ELG: People, Culture and Communities
  • Understanding the World ELG: The Natural World

Download progression document

Includes statements from Development Matters (birth to age five) and the relevant ELGs in full, for the Sensory bottles provocation

Characteristics of effective learning

Play, Be, C Units provide enabling environments with teaching and support from adults. Reflecting on the characteristics of effective teaching and learning, children will have opportunity to learn and develop by:

  • Playing and exploring – children investigate and experience things, and ‘have a go’.
  • Active learning – children concentrate and keep on trying if they encounter difficulties and enjoy achievements.
  • Creating and thinking critically – children have and develop their own ideas, make links between ideas, and develop strategies for doing things.

Early Years Foundation Stage Statutory Framework: accessed November 2024. Available under the Open Government Licence v3.0.

What you will need

Duration

10 minutes preparation, 10 minutes or so for the activity.

What you will need

Duration

  • 10 – 20 minutes to build and set up your dark den
  • 10 minutes or so.

STEM vocabulary to introduce

Float, sink, sunk, sank, rise, rose, risen, size, big, small, heavy, light, bottom, top, surface, under

What to do

  • Fill the bottles about three quarters full of water. Add food colouring if you wish to. Add a small amount of the material to be investigated. Put on the lid and secure with tape.
  • Tell the children they are going to be marine engineers and will be curious about which materials float and which sink. You could show the children the marine engineer poster or use our sensory bottle provocation.
  • Invite the children to investigate the bottles. Can they find out which bottles contain materials which sink and which contain materials which float?

Questions to ask to support and extend learning

  • Is the material floating or sinking?
  • Why do you think it is doing that?

What happens if….

  • You turn the bottle upside down?
  • On it’s side?
  • You shake the bottle?
  • You leave the bottle stood upright for a while?
  • Is there a way to make the material sink?
  • What would you like to put into a bottle?

Remember to refer to the children as marine engineers and praise them for using the attributes. You could say things like:

“You have been curious like a marine engineer and investigated whether the materials in the bottles float or sink…”

Other things to try

You could investigate which liquids are more dense and sink to the bottom of the bottle or are less dense and float to the top of the bottle with the children.

You could try tap water dyed with food colouring, oil, and sugar solution (sugar dissolved in water).

You could ask:

  • What happens to each layer?
  • What happens if you shake the bottle?

The science of marine engineering

We have put together some useful information about the science of marine engineering to accompany this activity. Don’t worry, this is for your information only and to help you answer any questions children may have. We don’t expect you to explain this to the children in your setting!

Why do some materials sink and some materials float?

There are two forces acting on objects in the water. The weight of the object pulls it down, while the upthrust of the water pushes it up. If you’ve tried to hold a beach ball, empty plastic bottle or inflatable under water, you will have felt this upthrust force pushing the object towards the surface. The upthrust force is equal to the weight of water displaced (pushed out of the way) by the object.

If the weight of the object is equal to, or less than, the upthrust, it floats. Things that float are buoyant. If the weight of the object is greater than the upthrust, the object will sink.

Why do some liquids float on top of others?

Density describes how much space an object or substance takes up (its volume) in relation to the amount of matter in that object or substance (its mass). More dense liquids, such as sugar solution or honey, will sink below less dense liquids, like water. Oil is less dense than water, so will float to the top.

© Northumbria University 2014-26