Hannah is boiling water in a glass tea kettle. She notices bubbles forming on the bottom of the kettle that rise to the top and wonders what is in the bubbles.

She asks her family what they think and this is what they say:
• Dad: They are bubbles of heat
• Calvin: The bubbles are filled with air
• Grandma: The bubbles are an invisible form of water
• Mom: They are empty
• Lucy: The bubbles contain Oxygen and Hydrogen that separated from the water
Which person do you most agree with and why?

Answer in full and complete sentences.