Reading Comprehension

PT113 · S1 · P2 · Q11 Marie Curie

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Spurred by the discovery that a substance containing uranium emitted radiation, Marie Curie began studying radioactivity in 1897.

Topic

Marie Curie's early research on radioactivity and its historical context

Framework

Old / New

Main Point

Marie Curie made foundational discoveries in radioactivity based on the evidence and scientific understanding available to her at the time, and any modern criticisms for not reaching later conclusions are misplaced because her work paved the way for those later breakthroughs. (Most Valuable Sentence: — last paragraph)

P1: Curie’s Pioneering Experiments

Marie Curie started her work on radioactivity after discovering that uranium emitted radiation. She found pitchblende was even more radioactive than uranium and, hypothesizing that a new element was responsible, discovered polonium and radium. She also noted that the emission rate for a given element seemed constant and couldn’t explain the underlying mechanism for radiation.

P2: Modern Understanding and Limits of Curie’s Evidence

Today we know that radiation is due to the decay of isotopes and that emission rates slowly decrease over time. Some have criticized Curie for not reaching these modern conclusions, but given what was available to her scientifically (especially since most radioactive isotopes of lighter elements don’t exist naturally), such criticisms are unfair.

P3: Scientific Context of Curie’s Era

During Curie’s time, the structure and nature of atoms were still being debated: physicists saw matter as eventually being indivisible, while chemists conveniently used the concept of atoms without worrying about whether atoms truly existed.

11.

The author's primary purpose in the passage is to

  1. Correct

    summarize some aspects of one

    Why this is right

    This answer actually touches on both the Highlight Noteworthy (summarize a scientist's work) and the Challenge Position (defend against criticism) aspects of the passage. The author summarized some aspects of Curie's work and defended her against the recent criticism that "she should have reached these conclusions [about where radiation comes from] herself".

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

    87% picked this

  2. describe a scientific dispute and

    Out of Scope

    Out of Scope: argue for earlier theory It's not clear what we would even match up with the phrase "earlier theory" or "scientific dispute". The passage is set around a time when radiation had just been discovered and was very poorly understood. Curie made some crucial observations and also some untrue speculations. Her guess at what radiation was would be what we could call 'the earlier theory', that radiating substances lose mass in the form of atoms. The author does not argue for the correctness of this theory. He admits that it's wrong but says, "Don't blame Curie for having an incorrect earlier theory. No one knew anything back then. Let's just thank her for the discoveries she made and the future discoveries she facilitated."

    2% picked this

  3. outline a currently accepted scientific

    Wrong Emphasis: theory vs. Curie

    Was this passage primarily about "currently accepted theories on radiation" or about Marie Curie? It is definitely more about the latter. Curie is in a majority of the sentences. The fact that this answer doesn't even have a placeholder noun for Curie tells us there's no way this is capturing the primary focus.

    5% picked this

  4. explain the mechanism by which

    Wrong Emphasis: where's Curie?

    Just like (C), this answer makes it seem like this wasn't primarily a passage about Marie Curie. She appeared in the first sentence, the last sentence, and most of the ones in between. The author's primary purpose in writing this passage was to talk about Curie's discoveries and answer her recent critics. It wasn't to "explain the mechanism by which radiation occurs". That only happens in one sentence at the beginning of the 3rd paragraph.

    5% picked this

  5. discover the antecedents of a

    Out of Scope

    Out of Scope: argue not an advance We could similarly reject this answer since it doesn't reference Curie, who was the primary focus of the passage. It's also the case that this author never argued that our modern understanding of radiation "is not a genuine advance over Curie's understanding of radiation". He knows she didn't understand it well / correctly and forgives her for that.

    1% picked this

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