Although fullerenes - spherical molecules made entirely of

[tim]

It sounds like you have a pretty low bar for what you consider irrelevant. For that reason, I would recommend that you completely disregard any question of relevance when you're considering answer choices, at least until you get more used to identifying what is clearly irrelevant in answer choices. Hint: If the answer choice mentions fullerines at all, you should probably not consider it irrelevant, unless is says something ridiculous like "fullerines are tasty".

Note to other students: this does not mean that no one should eliminate answer choices that are irrelevant. It's just that this poster was a little overzealous in declaring the irrelevance of some answer choices.

[RonPurewal]

at the very least, you should be able to articulate WHY things are 'irrelevant'.

this could happen in one of two ways:
1/ a choice mentions X thing, or contains Y distinction, which does not affect the topic at hand (and is perhaps specifically excluded by the language of the prompt);
or
2/ any correct answer must do Z thing, and you're looking at a choice that doesn't.

here:
this problem is full of big words, but, at the end of the day, it boils down to this: "These things were formed in nature. We have also made them in the lab. Thus the conditions in nature must have been LIKE those in the lab."

if you want to show that this is wrong, then you MUST come up with something that differs between the lab fullerenes and the natural ones. any choice that does NOT draw such a distinction is 'irrelevant' (#2 above).

[RonPurewal]

also note that choice A is even worse, in the sense that it essentially tells you nothing.

the passage has already stated that people found xxxxx stuff. this is already a FACT.
choice A tells us that the people who found xxxxx stuff had to be very, very meticulous about their scientific methods. well, that's great, but we don't have any new information. so A does nothing whatsoever.

i guess you could regard this as the most general possible form of #2 above: if ANY choice is to strengthen or weaken an argument, it MUST present new information. (if you were on a jury, this would be obvious: if you want to strengthen or weaken the case for the prosecution or defense, then clearly you need to present some NEW evidence!)

[sahilk47]

Hi Stacey,
Thanks for your explanation.
I have a question here. What's the meaning of "previously unknown crystalline structure ". Does it mean that now the crystalline structure is known? If that is the case then it is a possibility that the fullerenes found in lab have the same crystalline structure. May be, after finding fullerenes, scientist got to know about this "previously unknown crystalline structure". I am just wondering, if this statement is true then can GMAC still mark debatable answers as correct?

"previously unknown" = unknown prior to THAT discovery.

the passage explicitly states that they were FIRST found in the lab, THEN in nature. therefore, if the natural forms were "previously unknown", they can't be the same as the lab forms.

Hi Ron

Can you please explain this point again? 'Previously unknown...' I am not able to understand how a previously unknown knowledge can stop geologists from evaluating their hypothesis about the state of Earth's crust?

Thank you

[RonPurewal]

if the structure was unknown until this discovery happened, then the fullerenes from the lab must have had a different structure.
thus we have two different types of chemicals, so there's no reason to think that one would give any meaningful information about the other.