Material Exploration: Density

In this activity, children will use their senses to explore the relative densities of household objects.

 Learning Objectives

  • Science Content Knowledge: Build basic knowledge about object properties affect density

  • Science Process Skills: observe, predict, classify, compare

  • Developmental Skills: inhibitory control, working memory

 Materials:

  • Tub with water

  • Rubber Duck

  • Egg

  • Apple

  • Crayon

  • Sponge

  • Pencil

  • Bottle Cap

  • Empty Water Bottle

  • Full Water Bottle

Supplemental Materials (worksheets etc.)

  • Sink or Float Experiment Worksheet

  • Object Icons Worksheet

Activity Instructions

Step 1: Investigate and Sort Materials

How dense an object is determines whether it will sink or float. Make observations about and compare the objects.

Compare the objects and order them from smallest to largest.

  1. How BIG is the object? Larger objects tend to displace more water, an important factor for an object’s buoyancy. Weigh the objects by holding in your hands or using a balance scale and put them in order from lightest to heaviest.

  2. How HEAVY is the object? The heavier the object is, the more likely it is to sink. Take a closer look! Find objects that have holes or empty spaces. Objects that contain pockets of air, such as sponges or wood, tend to float.

  3. Is the object POROUS? Can you find an object that has air inside? Can you find an object that has holes? Are they heavier objects or lighter objects?

 Classify! Use your observations to make a hypothesis about whether an object will sink or float and then sort them into two groups.

Science Background

In this activity, we can learn about object density and buoyancy through materials exploration and observation. There are three main things that make up an object's density: it’s size, weight, and structure (i.e., is it solid or does it have holes?). How dense an object is determines whether it will sink or float.

Sinking and FloatingNatasha ChlebuchQuick Hit