Official Solution:

Although fullerenes - spherical molecules made entirely of carbon - were first found in the laboratory, they have since been found in nature, formed in fissures of the rare mineral shungite. Since laboratory synthesis of fullerenes requires distinctive conditions of temperature and pressure, this discovery should give geologists a test case for evaluating hypotheses about the state of the Earth's crust at the time these naturally occurring fullerenes were formed.
Which of the following, if true, most seriously undermine the argument?


A. Confirming that the shungite genuinely contained fullerenes took careful experimentation
B. Some fullerenes have also been found on the remains of a small meteorite that collided with a spacecraft
C. The mineral shungnite itself contains large amount of carbon, from which fullerenes apparently formed
D. The naturally occurring fullerenes are arranged in a previously unknown crystalline structure
E. Shungite itself is only formed under distinctive conditions


D undermines the argument by attacking the premise by suggesting that naturally occurring fullerene and synthetic fullerene differ in their structure. Since the objects of comparison are not similar, the comparison between the conditions these were formed does not stand.

A) the effort which took to confirm fullerene presence in shungite is irrelevant to the argument. What matters is whether shungite contains fullerene or not.

B) This one is close. I almost fell for it. It seems to offer an alternate explanation for the formation of fullerene. But what should be considered is, even if fullerene is formed in outer space does that change anything if it is also formed in earth? No, it does not.

C) This one provides more evidence to the argument and thus is strengthening the argument.

E) This is the premise itself.


Answer: D
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I don't agree with the explanation. b is the right ans

I did not choose answer D because of the words "previously unknown crystalline structure",does this mean that this structure is not known at present ?
Experts please explain ..

Thank you
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This implies that the structure is known now, but it actually does not matter whether it is known now - the importatnt part is that, the structure of natural F was not known till it was discovered in nature.

First laboratory F (lab F) was synthesized - therefore the structure of lab F was already known before the discovery of natural F. Thereafter natural F (nat F) was discovered. Option D states that the crystalline structure of nat F is not previously known. This implies that the structure of nat F MUST be different from lab F. Hence the conditions at which both were created were not same. Hence laboratory conditions and earth conditions were not same. Hence laboratory synthesis of lab F cannot help in fidning out the condition of earth's crust during formation of natural F.

Very tricky one and good explanation.

Critical thinkers.

But how is it concluded that the one synthesized in lab is not crystalline? Please Explain.

Thanks!

It has not been concluded that the one synthesized in lab is not crystalline. The basis of reasoning is that the structure was not known before - both could have crystalline structure, but different from each other.

E. Shungite itself is only formed under distinctive conditions

My reasoning for E) is -
If Shugnite itself forms under distinctive conditions, then it would be tough for researchers to "evaluate the hypotheses about the state of the Earth's crust at the time these naturally occurring fullerenes were formed" since Shugnite and the F inside them could require different conditions. Conditions outside may not translate to the conditions inside the mineral. Researchers in this case would be looking for conditions required for F to validate their hypothesis but they would actually need to look for conditions required for the mineral.

I am not very convinced yet.

Let me talk about option D later. Let us first understand why B should be incorrect?

The argument says that Since laboratory synthesis of fullerenes requires distinctive conditions of temperature and pressure, this discovery should give geologists a test case for evaluating hypotheses about the state of the Earth's crust at the time these naturally occurring fullerenes were formed.

Now, if it get known that this fullerenes came from some meteorite, than the argument definitely gets weakened, because now geologist will NOT be able to evaluate hypotheses about the state of the Earth's crust at the time these fullerenes were found (i.e. in meteor remains). So B IS a correct answer.

Now, looking at D: I am not a chemistry expert, but if the structure is different, wouldn't that make it a different substance/different compound altogether? Then it will not be called fullerene. e.g. coal and diamond have different structures of carbon. Because they have different structures, they have different properties. So they are different substances. With this understanding, option D seems to be invalid altogether. (My understanding about chemical structures may not be 100% correct though).

Please share your thoughts!!!

I think this is a high-quality question and the explanation isn't clear enough, please elaborate. B. undermines the conclusion that the discovery will give a test case of studying earth's crust at the time of formation of fullerenes. Bcoz fullerenes may have come from the outer space.

Okay got it. Nice question. Notice "Naturally occuring" modifier. Classic case of generalization. Fell for B.
It points to the fact that naturally occurring structure and the laboratory structure are two different compounds.

Thanks,
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I think this is a high-quality question and I don't agree with the explanation. B gives a more logical explanation by which the argument can be undermined. If the fullerenes have come from an extra-terrestrial object, then the conclusion drawn by the author is flawed.

I don't quite agree with answer D and I believe B is more precise. The problem with D in my opinion is that even though it shows the synthetic fullerene and the naturally occurring fullerene are different, it does not undermine the possibility that the naturally occurring fullerene could shed light on how the earth's crust was in the past. Scientists could find out the specific conditions in which that crystalline structure forms and then use it to understand earth's past.

If you find those same fullerenes in meteorites, however, this might mean they formed in space and came to earth, so even if we find out about the specific conditions in which that crystalline structure forms, we cannot understand if it formed on earth's crust or a different planet/star, and brought here by such meteorites.

I think this is a high-quality question and I agree with explanation.

GMATNinja Can you help me understand why B is wrong and D is correct.
My thinking is that since, we dont know from the passage whether this unknown crysatlline structure is found in the current time, I considered D as wrong.

very tricky question with good explanation. I fell for B

Yes,

The argument does not hold when the mineral itself is formed under distinctive conditions but I think OG doesn't consider conditions of Mineral formation to support the argument when evaluating the hypothesis of lab-based and Natural occurring Fullerene.

For Declining Option E-
why there is an assumption that both distinctive conditon of forming LAb F and Nat S needs to be same.
Either could differ or may same. Thus interior condition for NAt F and outside mineral S does not matter.

Having said that, Knowing distinctive condion of Lab F can help evaluate the conditon of Earth crust provided the two NatF and Lab F is comparable.