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20.9 % (almost 21%)
Half a billion years ago the percentage was higher (in the mid-30s) due to abundant plant life. Before photosynthesis evolved, atmospheric oxygen was close to zero & poisonous to the earliest cells.
it is 21% oxygen,that is ok because it isn't good to breathe pure oxygen
Wiki User
∙ 8y ago
Wiki User
∙ 11y agothe approximate percentage by volume of oxygen present in earth atmosphere is 21%
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How has the earths atmosphere changed?
The earths atmosphere has significantly altered over the years. The process of the earth's atmosphere was recognized and evolved 2.7 billion years ago, forming the nitrogen-oxygen atmosphere that exists today. This change enabled the formation and beginning of the ozone layer (which along with magnetic fields) block solar radiation.
How do humans breathe Oxygen?
Yes. The air is 21% oxygen which is what humans run on. It is 79% nitrogen which we filter out. I learned this today in Health class.
Why did the earth's atmosphere change after it was first formed?
The earths atmosphere has significantly altered over the years. The process of the earth's atmosphere was recognized and evolved 2.7 billion years ago, forming the nitrogen-oxygen atmosphere that exists today. This change enabled the formation and beginning of the ozone layer (which along with magnetic fields) block solar radiation.
When did oxygen levels start to rise on Earth?
After the earth was created, there was just one gigantic ocean. At some point, single-celled organisms formed - the first plants. They made their own energy using the sun and carbon doixide (photosynthesis) and one of the waste products was oxygen. As they multiplied, more and more oxygen was produced, forming the start of today's atmosphere.
Why is it important to know the difference between science and pseudoscience?
because science is what makes organisms what they are today, and idrk what the other word is so figure it out yourself
What is a gas that was probably abundant in earths atmosphere 3.6 billion years ago and is still abundant today?
Oxygen
What gases make up the earths atmosphere today?
Nitrogen (78%), Oxygen (21%) and other (Carbon Dioxide, Argon: >1%)
What was the percentage of oxygen in prehistoric times?
It was about 60% higher than the 21% that is today. This is a reason for large animals that are today smaller due to lower amounts of oxygen in the atmosphere. Living things usually grow faster in higher percentages of oxygen.
What do you think earths atmosphere would be like today if life had not evolved on earth?
Almost no oxygen, lots of CO2, still mostly nitrogen.
How much percent oxygen present in your atmosphere?
the percentage of oxygen in the atmosphere today is about 20.95%. Or... if you round it you get the most common answer of 21%.
What is earths temperature today?
it is 65
How to measure oxygen using a lit candle?
Remember the percentage of oxygen in the world today is 21%. Get a lit candle and put it on water. Then put a beaker over the lit candle. The water should rise and fill up to 21% of the candle as there is 21% of oxygen in the world.
What gases were present in earths today atmosphere?
Nitrogen
How is Biogeochemistry used today?
biogeochemistry is used by earths atmosphere
Why pieces of earth's earliest crust do not exist today?
why do pieces of earths earliest crust not exist today
What do scientists think was the of the oxygen in earths atmosphere?
It came from primitive organisms early in earth's history. They were the first organisms to use photosynthesis to make food, by using light to convert Carbon dioxide and water into glucose (food) and oxygen. Since oxygen is a waste product of photosynthesis, it was released into the air. As more and more of these organisms multiplied, large amounts of oxygen were released into the air, forming today's atmosphere.
How has the earths atmosphere changed?
The earths atmosphere has significantly altered over the years. The process of the earth's atmosphere was recognized and evolved 2.7 billion years ago, forming the nitrogen-oxygen atmosphere that exists today. This change enabled the formation and beginning of the ozone layer (which along with magnetic fields) block solar radiation.
