Scientific Advancement and Nuclear Fission

Answer choices

1. A

   Correct67% picked this

   the results of experiments in neutron bombardment of uranium conducted by the physics community between

   Why this is right

   The relevant evidence, beginning of the 3rd paragraph, is the "puzzling group of radioactive substances produced by neutron bombardment of uranium." Those weird byproducts were some of the results of experiments bombarding uranium with neutrons. Where do these 1934 and 1939 dates come from? Well, the beginning of the passage indicates that 1934 is when Fermi first started bombarding uranium with neutrons, and 1939 is when Meitner made the breakthrough. That sentence, in the first paragraph, is saying, "Between 1934 ... and 1939 ... scientists compiled increasing evidence", in reference to this neutron bombardment of uranium.

   Skill tested: Meaning in Context · how this choice captures the passage's function is the move to repeat next time.

   67%
2. B

   Wrong Meitner Data8% picked this

   the results of related experiments in neutron bombardment of uranium conducted by

   The work by Meitner in Berlin, described at the beginning of the 3rd paragraph, is some of the relevant data. The work she did in 1938 when she escaped from Nazi Germany was related research but not the data her ultimate discovery came from. The data her discovery came from was that original data that her research partner Otto Hahn continued to experiment with and "kept her informed of".

   8%
3. C

   Wrong Data9% picked this

   the clear chemical evidence that Hahn had found of barium's being produced by neutron

   This data from Hahn was more of the proximate (immediate) cause of Meitner's breakthrough, but this question stem is asking about the relevant data that had been present for some time. Hahn's chemical evidence was not present for some time. When he presented it to Meitner, she figured out what it meant. The first sentence of the last paragraph points to Meitner's realization that "the relevant evidence had been present for some time" when it says, Meitner finally realized: the researchers had actually been splitting uranium atoms!

   9%
4. D

   Wrong Data9% picked this

   the fact that the sum of the number of protons and neutrons in the nuclei of barium and technetium was the same as the

   This is just like (C), in the sense that it's talking about the data that came from Hahn that triggered Meitner's breakthrough, but this question stem is asking about the relevant data that had been present for some time. Hahn's observation that barium + technetium add up to uranium was not "present for some time". I mean, in the sense that "the fact that the sum adds up" is based on numbers found on the periodic table, we could say this evidence was present for some time. But the last sentence of the passage isn't saying, "Meitner finally realized what the periodic table could have been telling her all along". It's saying, "Meitner finally realized what the neutron bombardment experiments could have been telling her all along."

   9%
5. E

   Not Scientific Data6% picked this

   the fact that radioactive products of neutron bombardment of uranium went unidentified

   This answer doesn't make any sense, because it's not referring to scientific data. The last sentence of the passage is saying, "the relevant data had been there for some time; we just didn't see what it meant until Meitner put it all together". This answer is saying "The fact that these byproducts went unidentified for so long" is the scientific data that Meitner finally interpreted. It's not saying she interpreted the byproducts as results of nuclear fission (which would be true). It's saying she interpreted "the fact that byproducts went unidentified" as the results of nuclear fission, which is a truly nonsensical sentence.

   6%