PrepTest 113

Topic: Science

Paragraph 1

• Paragraph note
  • Background on Curie's research on radioactivity (discovered polonium and radium in pitchblende, concluded emission rate is constant, couldn't locate mechanism)
• Views, minor Meta-Structures, and the author's attitude
  • Curies's findings:
    • Found two new elements in pitchblende: polonium and radium (fourth sentence)
    • Concluded that the radiation emission rate is constant (sixth sentence)
    • Curie couldn't explain the "mechanism" for radiation (last sentence)

Paragraph 2

• Paragraph note
  • Criticism of Curie (for not discovering the mechanism or realizing that emission rates decrease slowly) and author's rebuttal (it would have been impossible given the evidence)
• Views, minor Meta-Structures, and the author's attitude
  • Critics' view
    • We now know emission rates aren't constant (they decrease slowly over time) and that radiation occurs when isotopes decay, and Curie should have figured this out herself (first and second sentences)
  • Author's view:
    • It would have been impossible for Curie to make this conclusion with the evidence available to her, as the elements she would have needed aren't readily available in nature (second through last sentences)
  • Definition of "isotope": atom of the same element but different atomic structure (first sentence)
  • Author's opinion: "now known" (first sentence), "would have been impossible" (second sentence)

Paragraph 3

• Paragraph note
  • Author's rebuttal (debate on the nature of the atom in Curie's era)
• Views, minor Meta-Structures, and the author's attitude
  • Author's view:
    • The nature of the atom was still being debated in Curie's era (first sentence)
  • Comparison, according to the author:
    • Physicists believed that atoms were indivisible, while chemists used the atom as a way to conceptualize some reactions but weren't concerned about whether atoms existed (second and last sentences)
  • Author's opinion: "we must recall" (first sentence)

Paragraph 4

• Paragraph note
  • Author's rebuttal (Curie thought atoms were indivisible, couldn't conceive of atoms losing mass)
• Views, minor Meta-Structures, and the author's attitude
  • Author's view:
    • Curie couldn't have been expected to realize that atoms lose mass because she was committed to the idea of an indivisible atom (first and second sentences)
    • Further, her research helped pave the way for later breakthroughs in our understanding of atoms (last sentence)
  • Comparisons, according to the author:
    • Curie thought atoms were indivisible, so even if she thought that substances might lose mass by shedding atoms, this is a very different explanation of substances decaying when the atoms lose mass (first and second sentences)
  • Author's attitude: "very different" (first sentence) "could not be expected to have conceived" (second sentence), "understandable" (last sentence), "important to recognize" (last sentence), "paved the way for later breakthroughs" (last sentence)

Main Point: Curie's erroneous conclusions when investigating radiation are understandable and helped pave the way for later breakthroughs.

Rebutting Critics: We think the Rebutting Critics Meta-Structure best fits this passage's structure.* In a Rebutting Critics passage, the author presents criticisms of the subject matter before mounting a defense against those critiques. This pattern matches this passage's argument structure perfectly.

In the first paragraph, the passage introduces us to Madame Curie's investigation of radiation. After experimenting with various radioactive materials, she concluded that "the emission rate for a given element was constant" (P1, S6), but she could not "postulate a mechanism by which to explain radiation" (P1, S7). The second paragraph introduces a criticism of Curie's work. Modern science has since shown that some of Curie's ideas are wrong, and some critics have "faulted" her for not knowing better (P2, S2). Yet, our author tells us that Curie is not to be blamed for these inaccuracies. In fact, it would have been "impossible" for her to have discovered the truth about radioactivity.

In the following paragraphs, the author lays out several reasons why Curie's erroneous conclusions were understandable. Given the era in which she made her discoveries, she was limited in the materials and information available at the time. Complete explanations for the phenomenon she observed would only become possible with the help of more modern discoveries about radiation and the atom. The passage concludes by emphasizing that, although Curie was technically wrong, it was by no fault of her own, and she still succeeded in making crucial contributions to the world's understanding of radiation.

In a passage that utilizes a Rebutting Critics Meta-Structure, the main point will be the author's central defense. We should consider whether the author provides a conclusion summarizing their defense. If no conclusion is offered, we can summarize the defense for ourselves. In this case, the author provides a succinct summary of the argument in the last paragraph. There, we read, "not only is Curie's inability to identify the mechanism by which radiation occurs understandable, it is also important to recognize that it was Curie's investigation of radiation that paved the way for the later breakthroughs" (P4, S3). Since this sentence does such a good job of representing the main point, we should anticipate something that looks very similar.

*Since the author disagrees with the critics' viewpoint, you might see this as a Criticizing a Viewpoint or Correcting the Record passage. There is considerable overlap between these types of Meta-Structures, and investigating this passage with either structure would still help you understand the argument. You could even consider this an Innovative [Subject] passage, although you should still try to frame the main point as a response to criticisms.

This passage isn’t about understanding the science (few science passages are). It’s about understanding the author’s argument. And understanding the author’s argument doesn’t depend on understanding radioactivity or emission rates or isotopic decay or anything like that. It’s about seeing how the author responds to Curie’s critics!