Difference between Acne and Boils. Key Difference: Acne is the disorder of the skin that is caused by oil and/or debris clogged pore. It is characterized by a presence of pimples, blackheads and whiteheads. A boil occurs due to an infected hair follicle. The infection is usually caused by the bacteria known as Staphylococcus.
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.
I thought the average oxygen level was approximately 20.95 percent by volume? Both vary in space and time, but the variability of oxygen is much smaller than that of CO2. Your value for the oxygen concentration is close to the US Standard Atmosphere value of 20.9476%.