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LO: To understand the difference between sinking and floating.  


Key Words:


Buoyancy- How well something floats or sinks.

Float- To rest, move or hover slowly and lightly in liquid or in the air.

Sink- To go down below the surface of something, either under water or to the ground.

Density- The amount of stuff inside of it.


Can you think of any materials that float or sink when they are in water?

We know that if a material is heavy, the chances of it floating above the water is unlikely. However, if we had a lighter material, it would be likely that the item would float above the water.

Remember not all materials that are light float and not all materials that are heavy sink. We know that a piece of paper is light, but does this mean that in water it will float? We all know what happens to paper when it gets wet.


For your task:

  1. Watch the video below, which will help you understand about buoyancy.
  2. Once you have finished watching the video you will need to create a list of objects, and making predictions on whether or not you think these objects will sink or float.


An example has been done for you below.




Metal teaspoon






Prediction- Do you think the object will sink or float?


I think the metal teaspoon will float, because it is small and hollow.

Buoyancy: What Makes Something Float or Sink?

A quick and simple animation to help early-elementary aged kids understand the basic concepts of buoyancy (floating and sinking), density, and Archimedes' Pr...