## Property of Matter - Experimenting Cartesian Diver (Grades 3-4)

Overview
Science content
Science inquiry and process
Resources and materials
Pedagogical ideas - focus questions, exploration, invention, bridge, value claim, discovery
Definitions
Activity sequence
Lessons and activities detail

### Overview

Student observe a Cartesian Diver system and use their observations and understandings of sink, float, matter takes up space and can't occupy the same space as other matter at the same time, and mass as weight try to reason an explanation for what happens.

See video.

Properties of matter - When the bottle is squeezed, the air is pushed into the rubber on the dropper and expands, making more room for water to be pushed into the dropper making it heavier and causing it to sink.

### Science content - what science says (enduring understanding, big ideas, generalizations)

properties of matter as takes up space (volume), two objects can't occupy the same space, matter has weight or heavy, every object is made of matter.
When two object exert a force on each other the object with the greater force moves the object with the smaller force.

Supporting ideas from unpacking the big idea (facts, concepts, generalizations)

• Objects heavier than water float.
• Objects lighter than water sink.
• Water takes up space.
• Air takes up space.
• Water has volume.
• Air has volume.
• Water is matter.
• Air is matter.
• Objects can exert a force on each other.
• Water flows.
• Air flows.

### Science inquiry and processes - how science knows

Use of observations, systems and subsystems, evidence and reasoning to understand interactions in our world.

Supporting ideas from unpacking the big idea

• observations of eye dropper and the amount of water and air;
• isolate observations to the eye dropper subsystem
• Connection of observations to properties of matter - matter takes up space and can't occupy the same space as other matter at the same time, and matter has weight - mass.

### Resources and materials

Two liter plastic pop bottle, glass eye dropper, water.

Take the 2 liter plastic pop bottle, fill it with water, drop in an eyedropper with some water in it but not enough to make it sink, put the lid on tight, squeeze the bottle to make the dropper sink, and release the bottle to make it float. I will change the amount of water and air in the dropper and bottle to see how it changes the results.

### Pedagogical ideas

Focus questions - What causes a Cartesian diver (eyedropper) to sink and float?

Misconception - Air goes out of the eyedropper. Water goes into the eyedropper.

Exploration - Results The water went up into the dropper the more the bottle was squeezed. It appeared the air left and returned but there were no bubbles observed leaving the dropper. The more water in the dropper the lower it floated or sunk. The more air in the dropper the higher it floated. The more air in the bottle the harder you had to squeeze to get the dropper to sink.

Invention -

Bridges - Drawing of before and after pictures that include enough information to create an operational definition. - Observational evidence included on the diagrams - the dropper floated, the dropper sunk when the bottle was squeezed, the air remained inside the dropper since no bubbles were observed leaving the dropper, the air must, and the amount of water in the dropper increased when the bottle was squeezed.

Operational definition - When the bottle is squeezed the water pushes the air into the dropper so it is squeezed into a smaller space/volume. Making more room for more water to flow into the dropper. With more water in the dropper system it was heavier so it sunk. When the pressure was released the ....

Discovery, application, extension -

Value Claims - It's amazing how when you really observe something you can figure out what is happening.

### Definitions

• push
• pressure
• properties of matter as takes up space (volume), two objects can't occupy the same space, matter has weight or heavy, every object is made of matter.

### Activity sequence

1. Cartesian diver exploration;

### Lesson and activity details

Ask what will happen when plastic bottle was squeezed.