When it comes to maintaining life on earth, there is no element as important as oxygen. Without this element, we would be dead in no time! Invisible and odourless, it quietly continues to sustain and nourish life in nature. No doubt, oxygen is synonymous with life.
Oxygen makes up one fifth of the earth’s atmosphere. It comes third in terms of its abundance by mass in the entire Universe. The reason for its high concentration on the Earth’s atmosphere is the oxygen cycle in our planet. It is driven by photosynthesis of plants. The density level of oxygen becomes less, as altitude increases. Mountaineers find it difficult to breathe and have to slowly adjust to the decreasing oxygen levels as they climb higher. Astronauts carry their oxygen when they travel to outer space because there is no oxygen there.
At the same time, too much oxygen is also not good. Do you know that humans cannot survive if the oxygen level goes beyond 25 per cent? The same applies when the level goes below 17 per cent as well. Its atomic number is eight, and the symbol is O.
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