Through the process of photosynthesis algae and later plants used the energy of sunlight to convert water and carbon dioxide into sugar and oxygen. Oxygen levels rose until they reached a high point of 36% about 300 million years ago. Climate shifts and changes in life on Earth later caused some of that oxygen to go back into carbon dioxide, which was sequestered in carbonate rocks, and oxygen levels began to fluctuate. Currently, oxygen levels are at about 21% but that may change over the next few million years.
The first plants are thought to be the ancestors of green and purple algae. Over several billion years, oxygen began to build up as plants grew in number and diversified.
The first plants are thought to be the ancestors of green and purple algae. Over several billion years, oxygen began to build up as plants grew in number and diversified.
The free oxygen bubbled up from the oceans.
Plants
they come from earths atmosphere and gases
Scientist theorize that bacteria with chlorophyll in them slowly but surely began to multiply. And as they did, they photosynthesized enough to create an entire atmosphere. (as you know oxygen is a byproduct of photosynthesis)
The earths first atmosphere was created by the methane, carbon dioxide, sulphur oxides and water vapor that volcanoes were pumping out. Oxygen started to come in noticeable quantities once life had formed. Nitrogen is inert, so doesn't do anything.
It is a meteorite (meteor).
The oxygen most often comes from the atmosphere which is 21% oxygen.
Yes. Asteroids can enter earth's atmosphere. In such an event the asteroid will probably strike earth's surface.
Water molecules are formed by the reaction between hydrogen and oxygen.
It is the Oxygen from the CO2 and H2O tat they use to make sugars.
Plants produce oxygen through photosynthesis and release it into the atmosphere where we can breathe it.
No. Earth's atmosphere most likely originate from volcanic atmosphere. The oxygen is produced by plants.