Treatments. 1  Soak washcloth in warm water. 2  Dab washcloth on the boil. 3  This treatment allows the pus seeping out of bump, and as the result the boil will shrink.
The earth's atmosphere is approximatively 21% oxygen (really about 20.95%). 78% is nitrogen. The rest is a small mixture of other gases. 7 people found this useful.
Today oxygen makes up about 20 percent of Earth's atmosphere, but for the first two billion years after Earth formed, its atmosphere was anoxic (oxygen-free). About 2.3 billion years ago, oxygen increased from a trace gas to perhaps one percent of Earth's atmosphere.Another jump took place about 600 million years ago, paving the way for multi-cellular life forms to expand during the Cambrian Explosion.ndeed, the jumps in atmospheric oxygen at 2.3 billion years ago and 600 million years ago do seem to be associated with Snowball Earth episodes (Fig. 14). However, scientists are still unsure exactly what the connection might be between the extreme ice ages and changes in the oxygen content of the atmosphere.