- In 1771, Swedish pharmacist Carl Wilhelm Scheele discovered oxygen, but Scheele published his finding until six years later, so British chemist Joseph Priestley who discovered oxygen in 1774 got the credit for the discovery.
- The earliest photosynthesis formed about 3.5 billion years ago, so there was almost no free oxygen gas existed on earth before that.
- Oxygen is the most abundant element in the earth’s surface, it is necessary to human life, it exists in the water we drink and the air we breathe,its volume accounts for21% of the earth’s atmosphere.
- Mars’ atmosphere contains 0.15% oxygen, and about 1% of the Sun’s mass consists of oxygen.
- Oxygen is the most abundant element in the human body, it makes up 2/3 of the body’s mass.
- Oxygen was once used as the atomic weight standard, and then it was replaced by carbon-12 in 1961.
- Beautiful colors of the aurora borealis depend on the high-altitude atmospheric components. Excited oxygen can produce bright red and yellow-green colors of the aurora borealis.
- Oxygen itself will not burn, but it is one of the indispensable conditions for combustion, liquid oxygen is used as the accelerant for rocket fuel.
- It is calculated that more than 6 billion tons of oxygen are consumed by humans every year and the world’s green plants produce about 100 billion tons each year.
- Oxygen’s name derives from the Greek word “oxygenes” which means “acid producer”, so called because the early chemists considered oxygen was essential to all acids.
- On average, the oxygen in the atmosphere will be updated once every 2000 years through photosynthesis.
- Green algae and blue green algae can produce more than 70 percentage of the earth’s oxygen, they are considered to be the major source of atmospheric oxygen.
