Questions tagged [oxygen]

Questions regarding the 8th chemical element, a main component of the athmosphere and of the crust.

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16
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2answers
2k views

How is the equilibrium of 21% oxygen in Earth's atmosphere established?

The atmosphere is 21% oxygen. I assume that there must be an equilibrium between processes that produce oxygen (e.g. photosynthesis) and those that consume oxygen (e.g. aerobic respiration). Moreover,...
9
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1answer
2k views

When did wildfires start to occur on earth?

An oxidizer, fuel, and heat are needed for a fire. When considering oxygen as the oxidizer, an oxygen concentration of approximately 16% is required for combustion. Plant material is the fuel ...
8
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2answers
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Is oxygen the most abundant element on Earth?

When I was in school, I was taught that we need oxygen to breathe, but it actually constitutes only a small fraction of the atmospheric composition, and that nitrogen constituted the largest fraction ...
6
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2answers
5k views

Is oxygen spread equally on Earth's surface?

We know that oxygen comes from trees and plants (photosynthesis), so in the jungle where there are a lot of trees you would expect more oxygen than in the desert where there are no trees. Walking in ...
5
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2answers
368 views

Why did the carboniferous period have so much atmospheric oxygen?

Even if all the carbon dioxide (which makes up less than 1% of the atmosphere) in the air were sequestered by plants, would the atmosphere not remain about 21% oxygen? Why did the carboniferous period ...
5
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1answer
58 views

Are there any consequences to carbon capture and storage that also sequesters oxygen?

A big argument for carbon capture and storage is true reversal; while switching to renewable energy and eliminating CO2 emissions is a must, it will not reverse the massive movement of carbon from ...
4
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3answers
339 views

Why is it said that Amazon creates 20% of the oxygen production of the world, when it accounts with less than 14-12.8% of the forest area?

Many times we see in articles that the Amazon rainforest creates 20% of the oxygen of the world . Even french president Macron stated this in a tweet Macron tweet According to this Amazonas size ...
4
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1answer
133 views

Difference between the oxygen/$CO_2$ ratio during the period of the dinosaurs and the present

Here's the base of my question: Was volcanic activity more prevalent when the dinosaurs roamed? Is it true that during the time of the dinosaurs, both the oxygen requirements (by all living creatures ...
4
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2answers
251 views

How is there enough $\ce{O2}$ in the atmosphere to breathe if you are in a desert with no plants?

Humans depend on $\ce{O2}$ for breathing. The source of $\ce{O2}$ is photosynthesis by plants or cyanobacteria in the ocean. How is it, that when people travel through deserts or the Arctic / ...
4
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1answer
888 views

Causes of fluctuations in atmospheric oxygen in past 300 Mya

I have two questions based on the history of atmospheric oxygen levels depicted below. Source: https://commons.wikimedia.org/wiki/File:Sauerstoffgehalt-1000mj2.png. The notes below the chart explain ...
4
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1answer
140 views

Percentage of Oxgen left after burning all the available biomass

A documentry stated that during the Permian asteroid strike the atmosphere heated up to above 400C, potentially to 600C. As this would ignite most of the biomass, including us, I wondered if this fire ...
4
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1answer
843 views

Which plant produces the most oxygen?

Which plant is the most efficient in making oxygen for it's weight? I want to think it is the greenest plant with more leaves and least ...
3
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1answer
227 views

Why is Great Oxidation Event associated with Iron oxidation but not Aluminum or Silicon?

Just to build up on my previous success with oxygen origin in the atmosphere, I want to expand the question as was advised in the answers. The official heresy, despite denied in the comments and ...
3
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1answer
323 views

What rate of deforestation would be needed until we run out of oxygen?

I was wondering about how much unchecked deforestation would have to occur before we tipped the balance and started using more oxygen than was being replenished by plants and trees. Last I heard it ...
2
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1answer
163 views

Could earth run out of O2? [closed]

Death in a closed environment due to lack of O2 is actually not that bad: https://www.youtube.com/watch?v=kUfF2MTnqAw And as far as I know as we are cutting down our life saving woods and jungles ...
2
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2answers
124 views

What is the history of atmospheric O₂ concentration?

(This is about O₂, not CO₂) How did the concentration of oxygen change? Over geologic time frames since plants began to produce it, and during the time since the carbon dioxide increase caused by ...
2
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1answer
74 views

Why does atmospheric oxygen remain so “constant”? [duplicate]

I've always wondering why the oxygen in the atmosphere remains so perfectly at the level required for air-breathing life. What causes it to remain so perfect? Also, a side question, why aren't their ...
2
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2answers
51 views

How many mole of oxygen gas is there in the atmosphere?

At standard conditions, one liter of air, 0.21 L of oxygen gas, contains 0.0094 moles of $\rm O_2$. What is the total quantity of oxygen gas molecules in the atmosphere?
1
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1answer
319 views

Why limestone formation was not a concern in atmosphere oxidation event? [closed]

I have just got to know why Fe was a problem. After clay (alumnum) and Silicon got oxidized, there has left a lot of unoxidized Fe in the crust, whose oxidization has finished during GOE. But, ferrum ...
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0answers
66 views

Locate people by Oxygen/Carbon Dioxide levels [closed]

I've been challenged to think of some really out-of-the-box ways to locate people, and I had one. I'm 90% sure this isn't reasonably possible (probably only in laboratory settings), but I couldn't ...
0
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1answer
18 views

Filtered pressured oxygen 80 miilion years ago

Was dinosaur blood really red? Was the vegitation really green?Can that filter be used today?
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2answers
559 views

Why cannot people burn all the atmospheric oxygen? [closed]

We are told that photosynthesis, developed a couple of billion years ago has produced all the atmospheric oxygen. I wonder, why did the process stop? Why do modern plants prefer to recover the entropy ...