Ghost bubble

Materials

• Dry ice
• Large bowl
• Dish towel
• Dish detergent
• Water
• Ruler

Instructions

• STEP 1: Fill the bowl halfway with warm water. Describe and classify the water by using its observable properties.
• STEP 2: Using gloves, add a piece of dry ice to the bowl of warm water. Describe and classify the dry ice by using its observable properties.
• STEP 3: Using scissors, remove a long strip from the dish towel. Wet the strip of towel. Squeeze some of the detergent onto the strip of towel. Describe and classify the detergent by using its observable properties.
• STEP 4: Drag the soapy strip of towel along the top of the bowl, so a bubble forms on top of the bowl of warm water and dry ice.
• STEP 5: Using the ruler, make observations and measurements of the bubble, based on its properties, to determine how big the bubble will get before popping each time.

Explanation

When dry ice is placed into the warm water, a cloud (or "ghost") forms. Dry ice is frozen carbon dioxide gas and is -109.3 degrees Fahrenheit. As dry ice breaks down, it turns directly into carbon dioxide gas. When matter goes from a solid to a gas, it's called sublimation. The bubble is filled with the ghost or cloud, which is created by the dry ice sublimating. When the bubble pops, the ghost or cloud escapes.