Sink or Swim? Water Activity

By Sarah Haverstock, Mingan Archipelago National Park Reserve, QC

When families with young children visit the Mingan Archipelago National Park Reserve, where I work, the first place they usually head to is the water’s edge. There’s so much to explore in and around the water, and water play can lead to fun with science too.

This Club Parka activity gives budding scientists a chance to conduct an experiment, make predictions and observations, and try to figure out why things happen the way they do. It’s even more fun if the kids help find the items to test – which ones will sink or float?

Necessary material
First step
Second step

You will need:

  • A plastic wash tub or large container filled with water
  • A selection of small items to test – things from nature (leaves, twigs, pebbles, feathers), the kitchen (an egg, cork, spoon) or the toy box

Instructions :

  1. Hold up each object and ask for predictions: will it sink or will it float? (Kids can take turns placing the items in the water and making observations.)
  2. Continue until all the objects are in the water.
  3. Any surprises? Share ideas about what happened.

I’ve found that it isn’t essential to explain the science behind the experiment, but you can use a small toy boat to demonstrate what’s going on when things float:

  • When you set the boat in the tub, the boat pushes aside some of the water to make room for itself. The water pushes back across the bottom and along the sides of the boat. That’s called buoyancy and it’s what holds the boat up in the water.

Science is about asking questions and kids have lots of those! Our sink-or-float experiment usually triggers all kinds of questions about water – Where does it come from? Where does it go? Do all animals need water? – and can open the door to some interesting discussions, like the need to keep our lakes, rivers and oceans clean for all living things (including us!) to survive.

Happy experimenting!

P.S. Just for fun, try this tongue twister with the kids. Say “toy boat” as many times as you can as fast as you can!

Download this activity (PDF, 558 Kb)

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