Water Baloon in a Bottle Science Demonstration for Grade 3

Title: Water Balloon in a Bottle

Topic: Matter/particles/pressure

Grade: 3

Environment: Classroom, over a sink

Materials: 

• Balloons
• 3 plastic pop bottles (two with a small hole)
• Water
• Lighter
• Paper clip
• Sticky tack or tape

Curricular connections:

• Big Idea: All matter is made of particles
• Content: matter is anything that has mass and takes up space
• Competency: make predictions based on prior knowledge

Background knowledge: 

• Understanding of what matter is
• Understanding of what a particle is
• basic understanding of the states of matter

Learning Objective: 

• Reinforce that all matter takes up space
• Students will understand that air contains particles; the smallest possible unit of matter

Preparation:

In this demonstration we will show how a filled water balloon can be put inside a regular plastic pop bottle. 

• Before the demonstration, make one large water balloon
• Poke a hole in two of the bottles. Use the lighter to heat up the end of a paper clip and then push it through the bottle. 
• To create the example of a water balloon in a bottle, get one balloon and one of the bottles with a hole.
  • Put the balloon inside the bottle, then stretch the balloon over the lip of the bottle. 
  • Blow up the balloon inside the bottle as much as possible. 
  • Cover the hole with sticky tack/tape and then fill the balloon with water. 
  • Let go of the hole and tie the balloon (CAUTION: water will spray out).
• Set aside one bottle with a hole and a balloon for the demonstrator to use.
• Set aside the last bottle, which should not have a hole, and a balloon for a volunteer to use. 

Procedure:

Question/Prompts: Today we are going to be trying to figure out how to put a water balloon into a bottle. Before we start, there are a few words that we should review (write MATTER and PARTICLE on the board).

Does anyone know what these words mean?

How are they related?

What are the different states of matter?

Can anyone give an example of the different states of matter?

• The students will be shown a water bottle with a water balloon inside of it. 

Questions/Prompts: How do you think we got the water balloon into the bottle?

• One volunteer will be given a full water balloon and an empty pop bottle and asked to attempt to push the balloon through the opening. 

Questions/Prompts: Do you think we can push it through the opening of the bottle? Why or why not?

What will happen when your friend tries to push the water balloon through the opening? Why?

• When this is unsuccessful, the class will be shown an empty balloon and the empty bottle and asked to come up with ideas of how the water balloon was put into the bottle. 
• Another volunteer will be given an empty balloon and an empty bottle and asked to try some of the classes theories.

Questions/Prompts: Do you think XX will work? Why or why not? 

• If not suggested, the volunteer will be prompted to stretch the balloon over the lip of the bottle and blow it up to make space for water to be poured in. 
• The student will not be able to blow up the balloon. A demonstrator will then attempt to blow up a balloon in the same manner but in a bottle that has a secret hole in the bottom. While the hole is open, the demonstrator will be able to blow up the balloon.

Questions/Prompts: Why do you think we can’t blow up the balloon?

Why do you think I (the demonstrator) could blow mine up?

Is there anything different about my bottle?

• The demonstrator will then show the hole to the class. 

Questions/Prompts: Why would having a hole in the bottle make it possible to blow the balloon up?

What happens when we put a hole in the bottle?

Can you feel anything from outside the hole when the balloon is being blown up?

Is there anything in the bottle before we put the balloon in?

What is air made of?

What do we know about particles?

Is there matter in air?

What do we know about matter?

• The demonstrator will put a hole in the volunteers bottle so that they can blow up their balloon (then hold the hole shut so that it stays inflated inside the bottle), fill it with water and tie it off. 
• Now the volunteer should have a full water balloon in the bottle and the class can continue their discussion.

Explanation:

• A regular empty pop bottle is not actually “empty”; it contains air which is made up of particles
• As particles are the smallest unit of matter, they take up space.
• The balloon can not be blown up or filled inside the bottle because the bottle is already full and there is no room.
• Adding a small hole in the bottle allows the air already in the bottle to move out as the balloon is blown up.

Safety Concerns/ Considerations:

• Have extra balloons on hand in case of defects
• Each participant, including the demonstrator, should have their own balloon
• Poking a hole in the bottle requires the use of fire and a hot paper clip, to avoid students’ burning themselves, this can be done by a teacher
• Some students may struggle to blow or tie up a balloon, check with students before they are chosen
• When taking the balloon off the lip of the bottle to tie, water tends to shoot out of the balloon and could cause volunteers to get wet 
  • If this is a concern, have towels and garbage bags with holes cut out to wear over clothes
• The water balloon could break while a volunteer is trying to push it into the bottle

Extensions: 

• Is there a way we could push the air out of the bottle without putting a hole in it? 
  • This could lead to another demonstration in which a water balloon is placed over a glass jar that contains a match. The balloon acts as a one way valve for hot air to escape and eventually falls into the jar.
• What is pressure and how does it relate to the demonstration?
• What are the different forms of matter used in the experiment?
• Leading on from the idea that particles make up atoms, what type of atoms compose air?