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Questions tagged [oxygen]

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

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17 votes
2 answers
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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,...
Irigi's user avatar
  • 573
9 votes
2 answers
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 ...
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9 votes
2 answers
39k views

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 ...
Matthew Layton's user avatar
9 votes
2 answers
12k 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 ...
Marijn 's user avatar
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5 votes
2 answers
3k 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 ...
Neil G's user avatar
  • 153
5 votes
1 answer
227 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 ...
BatWannaBe's user avatar
5 votes
1 answer
4k 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 ...
Muze's user avatar
  • 1
5 votes
0 answers
38 views

Carbon emission from estuaries

I've heard that estuaries like Chesapeake Bay produce a lot of methane during anoxic conditions. Is there a chance of these estuaries emitting significant amounts of CH4 in the future (because of the ...
Victor1995's user avatar
4 votes
3 answers
2k 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 ...
Pablo's user avatar
  • 1,137
4 votes
1 answer
145 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 ...
Yordan's user avatar
  • 141
4 votes
1 answer
331 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 ...
Little Alien's user avatar
4 votes
2 answers
4k 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 ...
J.G.'s user avatar
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4 votes
2 answers
577 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 / ...
Jake's user avatar
  • 143
4 votes
1 answer
326 views

As the number of ocean dead zones increases, is the world's primary source of atmospheric oxygen (phytoplankton) at risk?

Disclaimer: I am not a scientist. I was wondering if there is a concern that the world will run out of breathable atmospheric oxygen as the number of dead zones in the ocean increases with global ...
user21456's user avatar
4 votes
2 answers
461 views

Are we consuming more oxygen than the world is producing due to fossil fuels?

With the disclaimer than I am not a scientist, my understanding is that the earth developed a surplus of atmospheric oxygen over the eons because a small percentage of photosynthetic organisms were ...
user21456's user avatar
4 votes
1 answer
171 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 ...
Bob Hay's user avatar
  • 41
4 votes
0 answers
98 views

Oxygen-18 in saline water and freshwater

Which has higher $\delta {}^{18} \text{O}$, saline water or freshwater? I searched for this question and found many researches about the relationship between $\delta {}^{18} \text{O}$ and salinity. ...
Kernel's user avatar
  • 41
3 votes
1 answer
670 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 ...
Steji's user avatar
  • 133
3 votes
0 answers
29 views

How does the partial pressure of oxygen relate to its concentration in water?

I've read that the partial pressure of oxygen in water will be the same as the partial pressure of oxygen in the atmosphere, but that the saturation of oxygen in water is dependent on factors like ...
Elhammo's user avatar
  • 233
3 votes
0 answers
49 views

What is the atmospheric percentage of oxygen produced by trees and phytoplankton every year?

I know that every year carbon sinks remove ~20Gt of CO2 (about half of our emissions), and release a comparable amount of O2 , But I want to know how much O2 the carbon sinks produce annually ...
Victor1995's user avatar
2 votes
1 answer
334 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 ...
Emanuel Graf's user avatar
2 votes
2 answers
3k 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?
ElnorCat's user avatar
2 votes
2 answers
290 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 ...
Volker Siegel's user avatar
2 votes
1 answer
289 views

What was the oxygen concentration in the air during the late miocene period?

As the title says, I'd like to know what the O2 concentration was during the late Miocene period. I've tried to look this up but I'm having a hard time finding any conclusive data on it, or even any ...
micah's user avatar
  • 23
2 votes
1 answer
1k 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 ...
Chris's user avatar
  • 21
2 votes
0 answers
43 views

Assuming no nearby animal/plant life or other 'artifical' influences, would a trapped pocket of air under 50-60 meters of seawater be breathable?

My guess as to the answer to my own question: Over a long period of time, no matter what the original composition of the air pocket was, it will exchange gases with the seawater just below it, which ...
Gonzalo's user avatar
  • 21
2 votes
0 answers
47 views

Does oxygen propagate towards stronger magnetic fields on Earth?

I noticed Earth has variations in gravity similar to focal points for magnetic fields, both macro and micro in size, caused by magnetic material deposits. With oxygen being attracted to magnets, I ...
Justintimeforfun's user avatar
1 vote
1 answer
354 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 ...
Little Alien's user avatar
1 vote
3 answers
176 views

How could oxygen levels have ever been higher if there is so little carbon dioxide present?

Assumptions: Essentially all oxygen that's ever been present in the atmosphere originated from oxygenic photosynthesis. The production of an oxygen molecule during photosynthesis leads to the ...
Alessandro Power's user avatar
1 vote
1 answer
56 views

Terraforming and maintaining a habitable atmosphere on Mars

Since Mars core does not function like Earths does, would a planetary core "kick-starting and maintaining" device be needed in order to produce a magnetosphere required to preserve the ...
Bishop Switchfoot Keef Swet's user avatar
1 vote
1 answer
86 views

On the percentage of oxygen in the atmosphere

The percentage of oxygen in the atmosphere is 21 percent, according to NASA.gov. I was trying to make a mathematical calculation about oxygen consumption of humans, when I realised that there is a gap ...
SPANDAN DASH's user avatar
1 vote
1 answer
27 views

Filtered pressured oxygen 80 miilion years ago

Was dinosaur blood really red? Was the vegitation really green?Can that filter be used today?
Angel Tena's user avatar
1 vote
0 answers
14 views

Oxygen concentrations in the air and absorption rates at sea, even under windy conditions

If I measure the amount of oxygen in the air at sea, is it the same as if I measure it on land? What if there is wind? Does oxygen concentration, change, in the middle of wind? What about the ability ...
Joselin Jocklingson's user avatar
1 vote
0 answers
67 views

How long to breathe (the equivalent) of all of the atmosphere?

I have done some rough calculations of how long it might take humanity: approx 80,000 years (that's taking Earth's population as 7.5 billion, 11,000 litres a day of breathing per person, the weight of ...
Amphibio's user avatar
  • 366
1 vote
0 answers
74 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 ...
Chris Burrus's user avatar
0 votes
0 answers
39 views

Isotope fractionations

The isotopic fractionations in the precipitate are equilibrium fractionations and the evolution of a system can be described using Rayleigh destillation! The fractionation type during evaporation is ...
Weiss's user avatar
  • 2,003
-4 votes
2 answers
756 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 ...
Little Alien's user avatar
-4 votes
1 answer
2k views

How much nitrogen would you need to replace all oxygen in a room of 1,000 cubic feet? [closed]

Imagine a room of 10x10 feet in size with a 10 feet high ceiling. The air in the room consists of roughly 78 percent nitrogen and 21 percent oxygen. The windows are shut closed and the gap under the ...
Tim Menser's user avatar