# Questions tagged [oxygen]

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

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### 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 ...
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1 vote
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### 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 ...
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### 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. ...
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### 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 ...
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### 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 ...
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### 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 ...
233 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 ...
141 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 ...
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1 vote
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### 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 ...
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### 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 ...
2k 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?
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### 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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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
3k 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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1 vote
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### 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 ...
290 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 ...
688 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 ...
1 vote
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### 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 ...
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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 ...
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### 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 / ...
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### 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 ...
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