Nuclear fusion is a process whereby the nuclei of atoms are joined, or

Hey, can you please elaborate on the explanation?

Conclusion- Fusion was achieved since a measurable amount of He-4 was found in the air of the chamber.

Type- Weaken

Pre thinking- I need to prove that fusion was not achieved. That's all i can thought at first glance.

A) Helium-4 was not the only gas found in the experiment chamber.
- Let X be the other gas which is present in the chamber. I still don't know whether fusion was achieved.

(B) When fusion is achieved, it normally produces several by-products, including tritium and gamma rays.
- The premise never says that He-4 was the only gas found in the chamber. There might be other rays or gases produced. I need to weaken the conclusion by pointing out the "measurable amount of Helium-4 gas found in the chamber". This option does not add any value to my conclusion.

(C) 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.
- By this fact, i can say the amount of He-4 found in the chamber= amount of He-4 found in the ordinary air. If so, how can i say if fusion has really happened in the chamber? This weakens my conclusion.

(D) Helium-4 gas rapidly breaks down, forming ordinary helium gas after a few hours.
- May be but time and temperature can no where impact this argument.

(E) Nuclear fusion reactions are characterized by the release of large amounts of heat.
- As i said in B, it was never mentioned that He-4 was the only by-product found in the chamber. There might be heat produced during the process.

Nuclear fusion is a process whereby the nuclei of atoms are joined, or “fused,” and in which energy is released. One of the by-products of fusion is helium-4 gas. A recent fusion experiment was conducted using “heavy” water contained in a sealed flask. The flask was, in turn, contained in an air-filled chamber designed to eliminate extraneous vibration. After the experiment, a measurable amount of helium-4 gas was found in the air of the chamber. The experimenters cited this evidence in support of their conclusion that fusion had been achieved.

Which one of the following, if true, would cast doubt on the experimenters’ conclusion?

(A) Helium-4 was not the only gas found in the experiment chamber. - WRONG. Like B and E only.

(B) When fusion is achieved, it normally produces several by-products, including tritium and gamma rays. - WRONG. Not affecting the conclusion in any way.

(C) 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. - CORRECT. If not then it helps the conclusion otherwise breaks it as in the amount is normal.

(D) Helium-4 gas rapidly breaks down, forming ordinary helium gas after a few hours. - WRONG. Irrelevant.

(E) Nuclear fusion reactions are characterized by the release of large amounts of heat. - WRONG. Nothing about heat is conclusive enough to support the conclusion of the passage.

Answer C.