| Photo 1: | A cigarette is dipped in liquid oxygen for 30 seconds. |
| Photos 2, 3: | The cigarette is lit and within 3 seconds completely burns. |
| Photo 4: | The filter explodes at the end. |
The presence of oxygen is the basis for nearly every burning process. The fact that the earth's atmosphere contains only 21% oxygen makes it
possible to control burning processes without large technical expenditure. The use of pure oxygen leads to the results shown above.
Breathing pure oxygen over an extended period of time is toxic.
The absorption of visible light and the resulting blue color of the liquid oxygen flame can be traced to electron transitions
between different spin states. We shall not go into the theory here.
