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Tanzania [10]
3 years ago
9

How did oxygen come up to make 21% of the earth's present atmosphere?

Chemistry
1 answer:
MakcuM [25]3 years ago
4 0
Tiny organisms known as cyanobacteria, or blue-green algae.
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This answer is D or c
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Explain how intermolecular attractions between molecules influence the bulk of properties of a material
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<em><u>Intermolecular forces determine bulk properties, such as the melting points of solids and the boiling points of liquids. Liquids boil when the molecules have enough thermal energy to overcome the intermolecular attractive forces that hold them together, thereby forming bubbles of vapor within the liquid.</u></em>

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1. According to the fossil record, the first LAND plants were most likely pine trees. moss and ferns. flowering plants. 2. Scien
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It is true that earth was once covered with oceans and little dry land.

Explanation:

Over the course of around four billion years, the Earth's oceans have lost about a quarter of their original mass. Today the atmosphere is rich in oxygen, which reacts with both hydrogen and deuterium to recreate water, which falls back to the Earth's surface. So the vast bulk of the water on Earth is held in a closed system that prevents the planet from gradually drying out. According to the researchers,  the continents emerged relatively suddenly from an ocean that covered 95 percent of the Earth's surface. The appearance of large masses of dry land would have caused more extreme weather, changes in ocean currents and the emergence of proper seasons. In turn, these environmental changes may have led to rise in atmospheric oxygen that enabled the explosion of new life forms around 500 million years ago.

7 0
3 years ago
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A 5.5 g sample of a substance contains only carbon and oxygen. Carbon makes up 35% of the mass of the substance. The rest is mad
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We have been given the condition that carbon makes up 35% of the mass of the substance and the rest is made up of oxygen. With this, it can be concluded that 65% of the substance is made up of oxygen. If we let x be the mass of oxygen in the substance, the operation that would best represent the scenario is,

<span>                                       x = (0.65)(5.5 g)</span>

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  • <em><u>soap</u></em><em><u> </u></em>
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2 years ago
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