• + Create new collection
• Below are links to Science Learning Hub resources for primary teachers related to floating and sinking in the Physical World strand of the New Zealand Curriculum.

## Building Science Concepts: Floating and sinking

Explore the big ideas that underpin floating and sinking in this article. It is a partial replication of the Ministry of Education’s Building Science Concepts Book 37 Floating and Sinking: How Objects Behave in Water.

Will this float or sink? uses an interactive or paper-based graphic organiser to consider whether an object floats or sinks. Use it prior to a unit on floating and sinking to gauge students’ thinking and again during and after the unit as formative assessment.

These simple hands-on activities use exploration and play to observe and learn about the science concepts:

Explore aspects of floating and sinking using some of these ideas about the salinity and denseness of water.

• Water density – how does it change with temperature and salinity?
• Ocean density – further explores how salinity, temperature and depth all affect the density of seawater.
• Ocean salinity – learn how salinity affects the density of water and how it varies throughout the ocean.
• A sinking feeling – a level 4 Connected article that introduces the concepts underpinning floating and sinking in the context of a boat race. The teacher support materials provide curriculum links and include suggestions on how the article can be used to grow science capability in critiquing evidence.

## Activity ideas

Buoyancy in water – students make a Cartesian diver to demonstrate the relationship between volume, mass and density.

Floating eggs – students investigate water density by floating an egg in freshwater and saltwater.

Investigating sea water – students investigate some of the properties of seawater.

Temperature, salinity and water density – use this activity to help your students visualise differences in water density.

Density – students are introduced to the concept of density. They calculate the volume of various materials to determine and then rank their densities.

I always knew I’d have a career in science – I wasn’t sure what field of science or in what way I would contribute – but the logic of science, the discovery and the quest to understand the physical world fascinated me.

Dr Kim Currie

## Images

Images can be a great way to gather students’ ideas about floating and sinking, for example the Tip of the iceberg image shows how ice floats in salty seawater. Place an ice cube in a glass of water and observe if it floats in the same manner.

These are also good images to prompt observation and discussions:

Our Floating and sinking Pinterest board is full of related resources.

Published 7 July 2015, Updated 11 October 2022 Referencing Hub articles
Go to full glossary