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Evgesh-ka [11]
3 years ago
11

PLZZZZZZZZZZZZZZZZZZ15. As much as 90 percent of the oxygen in our atmosphere is the result of

Chemistry
2 answers:
vladimir2022 [97]3 years ago
7 0

Answer:

The correct answer is - option D. photosynthesis.

Explanation:

It is shown by the study that most of the atmospheric oxygen comes from the photosynthesis by plants as oxygen is the byproduct of the photosynthesis. Photosynthesis is the process that uses light energy, carbon dioxide, and water to produce food or glucose/sugar and release oxygen as the byproduct.

Many scientists believe that oceanic phytoplankton that releases oxygen by the photosynthesis process makes 80 to 85% of the total oxygen of the atmospheric oxygen.

Dvinal [7]3 years ago
3 0

Answer:

D. photosynthesis.

Explanation:

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Is hydrogen a molecule or compound
Ainat [17]
It is a molecule because hydrogen is an element.
An element is made up of molecules
7 0
3 years ago
100 POINTS PLEASE HELP (PHOTOS INCLUDED)
pshichka [43]

Answer:

Explanation:

3.

Knowns: 100mL of solution; concentration of 0.7M

Unknown: number of moles

Equation: number of moles = volume * concentration

Plug and Chug: number of moles = 100/1000 * 0.7 = 0.07 mole

Final Answer: 0.07mole

2.

Knowns: 5.50L of solution; concentration of 0.400M

Unknown: number of moles

Equation: number of moles = volume * concentration

Plug and Chug: number of moles = 5.5 * 0.4 = 2.20 mole

Final Answer: 2.20 mole

6 0
2 years ago
Read 2 more answers
Write the oxidation and reduction half reactions;
luda_lava [24]

Answer:

a)

Fe^{2+}⇒Fe^{3+}+e^-

Br_2+2e^-⇒2Br^-

b)

Mg⇒Mg^{2+}+2e^-

Cr^{3+}+e^-⇒Cr^{3+}

Explanation:

A)

Remember that positive number superscripts mean electrons lack and negative numbers mean electrons 'excess' (if we compare it with the neutral element). So, for the case of Fe2+ which is converted to Fe3+, we know that in Fe2+ there is a two electrons lack, while in Fe3+ there is a 3 electrons lack; it means that Fe2+ was converted to Fe3+ but releasing one electron:

Fe^{2+}⇒Fe^{3+}+e^-

The same analysis is applied to Br2; Br2 is a molecule which is said to have a zero superscript because it is an apolar covalent bond; and it is converted to Br-, which, according to what I wrote above, means that there is a one electron excess. So, Br2 must have received an electron in order to change to Br-; but Br2 can't change to Br- as simple as that because Br2 is a molecule, not an atom; it is a molecule that has two Br atoms, so, Br2 must give two Br- ions as products, but receiving one electron for each one:

Br_2+2e^-⇒2Br^-

b)

Applying the same, in Mg2+ there is a 2 electrons lack, and in Mg is not electron lack (its superscript is zero), so Mg must have released two electrons in order to change to Mg2+:

Mg⇒Mg^{2+}+2e^-

Cr3+ has a 3 electrons lack, and Cr2+ a two electrons one, so, Cr3+ must receive an electron to convert to Cr2+:

Cr^{3+}+e^-⇒Cr^{3+}

3 0
3 years ago
Read 2 more answers
At the same temperature, a freshwater lake frezzes but a salt water bay does not because
Alexandra [31]

Ocean water freezes at a lower temperature than freshwater. ... Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit , because of the salt in it.

3 0
3 years ago
Write a report on the implications of entropy to a Christian 500 words
Neko [114]
The universe is "running down," becoming randomly scattered and disorganized, tending to break down into its simple parts. Metals rust, parts wear out, dead organisms decay and turn to dust. The entropy of the universe is increasing.

The Bible provides an answer. A great amount of energy had to be expended to produce such great organization. As one scientist states the problem, energy was not enough. If you are asked to "reduce the entropy" of your room (put it in order), you certainly need to put in some effort (energy). But just adding energy is not enough. You could let loose a bull in your room, and it would expend a great deal of energy; however, that energy would not decrease but would increase the disorder of the room. Therefore, scientists know that to produce order, energy must be intelligently directed. Evolution requires that atoms and molecules assemble themselves into increasing order, but the science of thermodynamics assures us that the entire universe, when left to itself, is converting to disorder. The Apostle Paul referred to this concept when he said through inspiration that the entire earth is "subject to the bondage of decay." The original state required an intelligence to organize the complexities of the universe.

Christians, of course, have an answer to these perplexing questions: God. God is the Creator of the universe, the ultimate source of its energy and order. He created it with no entropy (no disorder). When man sinned, the universe began to increase in entropy (become more and more disordered). For Christians a discussion of energy, thermodynamics, and entropy is inspiring. These subjects invariably point us to the One who created the universe and sustains it by His power. Christians also know that His power will one day totally renew the universe and entropy will have no part in it.

Christians need never be afraid of science. God is in control of the universe and all the laws of the universe operate according to His will and design. Christians should be confident that they have the answers to the perplexing questions of nature.

Part 2

The above attitude allows christians to ignore questions that are difficult and this leads to mental complacency.

"This is gods work. I must not question or touch this". Is their motto.

When christians see difficult questions, such as entropy and creation, that is where they stop thinking and attribute it to god. They become intellectually crippled and refuse to make that one further step. It then halts progress until the shamen can integrate new knowledge into their mantra and dogma.

Science in general, tries to explain and understand and make further progress and additions to human knowledge. Christians will only try to understand what they have been taught and integrate any new knowledge when the older beliefs become untenable.
3 0
3 years ago
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