The passage is telling us that one of the byproducts of a fusion reaction is helium-4 gas. A recent fusion experiment was attempted in an air filled chamber. Helium-4 gas was found in the air of the chamber, thus a fusion reaction occurred.
This is a weaken question that requires us to select an answer choice that would undermine this conclusion. Is it possible that the presence of helium-4 gas could be explained by something other than a fusion reaction and thus in itself insufficient to conclude that the fusion experiment was successful?
The correct answer choice (C) tells us that helium-4 is present in ordinary air and the amount found in the chamber is the same as one would expect to find in ordinary air. This fact casts doubt on the conclusion because the only evidence cited in its support is the presence of helium-4 that could have been in that air-filled chamber all along rather than being a byproduct of fusion.
Does this help?
Let me know if you have any other questions.
nizhoniOctober 8, 2019
Hi there! Ok I maaaaay have found a breakthrough in doing these weaken questions and it might work for you too. So these are the steps I take:
Step 1: I identify the conclusion
Step 2: I identify the evidence that led to the given conclusion
Step 3: I evaluate the argument by identifying what is the connecting factor between the evidence and the conclusion.
Step 4 (my favorite): I make a guess as to what could be an alternative cause/reason that breaks the connection I identified.
Step 5: Then I look at the answer choices, and I've been noticing that the answer choice I select, which is the correct answer choice, is some version of the alternative cause/reason I predicted.
For this question:
Conclusion: Fusion was achieved
Evidence: 1) after an experiment helium-4 was found 2) helium-4 is a by-product of fusion
Connection b/w conclusion and evidence: the presence of helium-4
My guess at an alternative that breaks the connection: "Well...maybe helium-4 is also just present in non-fusion instances"
Answer Choice C was a version of this guess: "The amount of helium-4 found in the chamber's air did not exceed the amount of helium-4 that is found in ordinary air.
