This experiment is a fantastic introduction to prediction. Encourage lots of speaking and listening throughout. Allow and help your child to express themselves effectively. This activity is great for talking about the events in the past/present and future tenses. Encourage lots of critical thinking, help them to develop their own explanations/ connections of floating/sinking.
Key vocabulary: Floating, sinking, wooden, plastic, metal, water, splash, soak, sink, heavy, light, guess or predict.
Key questions: What is happening to the object? Which objects float? Which objects sink? Which objects soak up the water? Which objects disintegrate?
The activity:Collect a wide variety of objects from around the house. Place these into a basket. Place a bowl of water next to the objects. A plastic sheet, bag or table cloth to line the chosen area will help with any potential leaks. If the weather allows set up this activity in the garden. Encourage your child to examine each object and predict/guess what would happen when the object is placed in the water. Try to use open ended questions to encourage their critical thinking such as ‘Why does the cup float and the ball sink?’
There are endless possibilities to include in your basket: plastic toys, paper, tissue, a stone, a feather, a pencil, a coin, metal objects, a cardboard tube, an apple.
Challenge: Place similar objects into the basket such as a foam ball and a metal ball. Encourage prediction and discussion that the same object made from different materials reacts in opposing ways.
Challenge: Create a Venn Diagram and encourage your child to classify the objects into groups according to their predictions, those that will float and those that sink. Once they have carried out the activity, encourage them to go back to their predictions and check to see if they were correct.
You could prepare the names of the objects on post-it notes and encourage your child to place them into the correct group. This would allow your child to easily remove a prediction from the incorrect to the correct group. Alternatively you could ask your child to classify through pictures. Encourage them to draw pictures in the Venn diagram of the objects that floated/sank.
Health and safety: monitor your child’s exploration as water can pose a potential hazard. Ensure that your child understands that objects should not be placed into their mouths. Check all items for sharp edges or splinters.
This is such a simplistic yet fun and engaging activity for children.