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aalyn [17]
3 years ago
12

Which mixture of gases is thought to have made up Earth's early atmosphere? A. methane, oxygen, hydrogen, water vapor B. carbon

dioxide, nitrogen, oxygen, ozone C. hydrogen, water vapor, ammonia, methane, carbon dioxide D. ozone, water vapor, carbon dioxide, ammonia
Biology
1 answer:
zzz [600]3 years ago
3 0
The mixture of gases that is thought to have made up Earth's early atmosphere is hydrogen, water vapor, ammonia, methane, carbon dioxide<span>. This is previous to life so oxygen was not present because it was produced when green plants existed to produce oxgygen through photosynthesis. Ozone was absen and so the uv radiation entered the atmosphere and it is thought that (along with electrical discharges) could vave contributed to the formation of the first organic molecules from the given mixture of inorganic gases.</span>
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What is an advantage and disadvantage of using 4.5-7.5 pH paper?
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Answer:

The correct answer would be:

Advantage: helps in finding the exact ph value with a narrower range.

Disadvantage: You don't know the exact ph value on a regular scale.

Explanation:

The pH paper is a pH paper with a color indicator that helps in determining the pH value precisely between the 4.5 to 7.5 pH range. It is accurate in comparison to other pH papers such as 0-14 paper. One no need to guess the color between the different colors from various color mixtures as it has a more precise color reading that helps in finding accurate pH value in a narrow range.

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7 0
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<em>Another way, albeit less accurate, is to count the big squares between R-R intervals and instead of dividing it by 1500, you divide it by 300.</em>

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