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When life first came about 3.5 billion years ago, there most likely was no oxygen in the atmosphere. This fact is indicated by iron in rocks formed during that time: in an oxygen environment, Fe2+ oxygenates to Fe3+, or rust. During that time, there was no evidence for rust.
Plants evolved out of a "primordial soup", a mixture of elements and some form of energy like light, geothermal heat, etc. Experiments have shown that, given the chemicals that we know to have been around during that time (CO2, H2O, NH3, H2, etc.), the basic units for life were produced. This includes amino acids, carbohydrates, fatty acids, and nucleobases.
The first plants formed from this primordial soup are thought to be the ancestors of green and purple algae. With the evolution of plants, CO2 fixation began and O2 evolution occurred. Thus, over several billion years, oxygen began to build up as plants grew in number and diversified.
Currently, nitrogen takes up about 78% of the air we breath, oxygen takes up 21%, and a variety of other chemicals like water and CO2 represent the remaining 1%. Our bodies don't need 100% oxygen; in fact, oxygen can be toxic in large doses.
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What makes up 1 percent of Earth's atmosphere?
1 percent of the earths atmosphere is made of the following: - Argon (0.93%) - Carbon dioxide (0.03%) - Neon> trace - Helium> trace - Methane> trace - Krypton> trace - Xenon> trace - Hydrogen> trace - Ozone> trace 21% of earths atmosphere is made of oxygen 78% of earths atmosphere is made of nitrogen
What is the approximate percent of oxygen by volume present earths lower atmosphere?
Oxygen makes up about 21% of Earth's lower atmosphere by volume.
WHAT IS THEAPPROXIMANT PERCENT OF OXYGEN BY VOLUME PRESENT IN EARTHS LOWER ATMOSPHERE?
The approximate percentage of oxygen in Earth's lower atmosphere is around 21% by volume.
Which gas forms 21 percent of the Earth's atmosphere?
Oxygen forms 21 percent of the Earth's atmosphere.
What gas is 21 percent of the Earth's atmosphere?
Oxygen is the gas that makes up about 21 percent of the Earth's atmosphere.
How much of the earths atmosphere is made up of nitrogen and oxygen?
The earths atmosphere is made up of 78% nitrogen and 21% oxygen
What makes up 1 percent of Earth's atmosphere?
1 percent of the earths atmosphere is made of the following: - Argon (0.93%) - Carbon dioxide (0.03%) - Neon> trace - Helium> trace - Methane> trace - Krypton> trace - Xenon> trace - Hydrogen> trace - Ozone> trace 21% of earths atmosphere is made of oxygen 78% of earths atmosphere is made of nitrogen
What is the approximate percent of oxygen by volume present earths lower atmosphere?
Oxygen makes up about 21% of Earth's lower atmosphere by volume.
How much is the earth atmosphere is made up of nitrogen and oxygen?
The earths atmosphere is made up of 78% nitrogen and 21% oxygen
What are gases that make up the earths atmosphere?
The most prominent gases are nitrogen (78 percent), oxygen (21 percent) and argon (nine-tenths of a percent).
What percent of our atmosphere is made up of oxygen?
Approximately 21% of Earth's atmosphere is made up of oxygen.
WHAT IS THEAPPROXIMANT PERCENT OF OXYGEN BY VOLUME PRESENT IN EARTHS LOWER ATMOSPHERE?
The approximate percentage of oxygen in Earth's lower atmosphere is around 21% by volume.
Makes up 21 percent of the atmosphere?
Oxygen makes up 21% of the Earths atmosphere.
What gas is nearly 21 percent of earths atmosphere?
oxygen . hey people googling there science hw. join the club :)
Does the atmosphere contain 21 percent air?
No - out atmosphere is made up of approximately 78% Nitrogen, 21% Oxygen and 1% other gasses.
Which gas forms 21 percent of the Earth's atmosphere?
Oxygen forms 21 percent of the Earth's atmosphere.
What percent of the atmosphere is oxygen'?
21% of the atmosphere is oxygen.
