Air and atmosphere
Bubbles that float and sink
Carbon dioxide is used to blow bubbles which sink in air. Hydrogen or methane is used to blow bubbles which float in air. Bubbles which sink and then float can also be made.
The Greenhouse Effect
The role of atmospheric gases, in particular carbon dioxide, in ‘trapping’ radiation energy, causing a rise in the Earth’s temperature – the greenhouse effect – can be demonstrated using a powerful lamp.