Engineering Explorers

Step 1: Gather materials.

• Dishwashing liquid
• Plastic tablecloth to cover the table, if needed
• Straws
• Sugar
• Table or other flat surface
• Tablespoon and teaspoon for measuring
• Towel
• Warm water

Step 2: Introduce activity.

1. Tell the children that they are going to make bubble solutions and do a science activity with the solutions. If the children are younger, you can make the bubble solution yourself for the entire group.
2. If the children are making their own solutions, give them instructions. Say: "Put 2 tablespoons plus 2 teaspoons of water in a cup. Add 1 teaspoon of dishwashing liquid. Stir gently."
3. Explain that mixing dish soap with water forms a solution. Say: "A bubble is made up of water and air. You can form bubbles in any water, but they break pretty quickly. The bubbles last longer when the water is mixed with soap because the soap acts as a kind of glue. We call that a "bonding agent" and it helps keep the air in the bubble longer.
4. Say: ”When you blow a bubble, air is trapped by a thin film of your bubble mixture. This film is made of a layer of water sandwiched between two layers of soap."
5. Tell the children that they are now going to conduct a scientific investigation.

Step 3: Engage children in lesson activities.

1. Tell the children to dip their fingers into the bubble mixture and wet a small area (about the size of their hand) on the desk or table in front of them.
2. Tell the children to dip one end of their straws into the bubble solution so that the straws are completely coated.
3. Say: "Place the coated end of the straw or tube onto the bubble mixture on the table and blow gently into the other end of the straw to create a bubble or a mountain of bubbles."
4. Say: "Dip the straw back into the solution every time you want to blow another bubble."
5. Say: "Wetting the straw by dipping it into the bubble solution allows it to slip into the first bubble without popping it."
6. Now say: "Try doing the same thing with your fingers. Ask: "Can you poke your finger into your bubble without bursting it?"
7. Let the children experiment with blowing and poking to figure out what works and what doesn't work as they collaborate with their friends.

Step 4: Engineering vocabulary

• Bonding Agent: Something that joins or fastens things together
• Solution: A mixture that contains two or more unlike substances

Step 5: Extensions

The type of liquid detergent and soft or hard water you use can affect your bubbles:

• Soft water is good for bubbles. Hard water is bad for bubbles. If you live in an area with hard water and are having difficulties making good bubbles, try using distilled water.
• Dawn dishwashing soap is good for making bubbles. Johnson’s® Baby Shampoo also makes great bubbles.
• All bubble solutions work better if you make them the night before and let them sit in an open container.