Spurred by the discovery that a substance containing uranium emitted

Question

Spurred by the discovery that a substance
containing uranium emitted radiation, Marie Curie
began studying radioactivity in 1897. She first tested
gold and copper for radiation but found none. She then
  (5)   tested pitchblende, a mineral that was known to
contain uranium, and discovered that it was more
radioactive than uranium. Acting on the hypothesis that
pitchblende must contain at least one other radioactive
element, Curie was able to isolate a pair of previously
  (10)   unknown elements, polonium and radium. Turning
her attention to the rate of radioactive emission, she
discovered that uranium emitted radiation at a
consistent rate, even if heated or dissolved. Based on
these results, Curie concluded that the emission rate for
  (15)   a given element was constant. Furthermore, because
radiation appeared to be spontaneous, with no
discernible difference between radiating and
nonradiating elements, she was unable to postulate a
mechanism by which to explain radiation.

(20)   It is now known that radiation occurs when certain
isotopes (atoms of the same element that differ slightly
in their atomic structure) decay, and that emission rates
are not constant but decrease very slowly with time.
Some critics have recently faulted Curie for not
  (25)   reaching these conclusions herself, but it would have
been impossible for Curie to do so given the evidence
available to her. While relatively light elements such as
gold and copper occasionally have unstable (i.e.,
radioactive) isotopes, radioactive isotopes of most of
  (30)   these elements are not available in nature because
they have largely finished decaying and so have become
stable. Conversely, heavier elements such as uranium,
which decay into lighter elements in a process that
takes billions of years, are present in nature exclusively
  (35)   in radioactive form.

Furthermore, we must recall that in Curie’s time
the nature of the atom itself was still being debated.
Physicists believed that matter could not be divided
indefinitely but instead would eventually be reduced to
  (40)   its indivisible components. Chemists, on the other
hand, observing that chemical reactions took place as if
matter was composed of atomlike particles, used the
atom as a foundation for conceptualizing and
describing such reactions—but they were not
  (45)   ultimately concerned with the question of whether or
not such indivisible atoms actually existed.

As a physicist, Curie conjectured that radiating
substances might lose mass in the form of atoms, but
this idea is very different from the explanation
  (50)   eventually arrived at. It was not until the 1930s that
advances in quantum mechanics overthrew the earlier
understanding of the atom and showed that radiation
occurs because the atoms themselves lose mass—a
hypothesis that Curie, committed to the indivisible
  (55)   atom, could not be expected to have conceived of.
Moreover, 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
  (60)   later breakthroughs.    1 
 1. Which one of the following most accurately states the central idea of the passage?

(A) It is unlikely that quantum mechanics would have been developed without the theoretical contributions of Marie Curie toward an understanding of the nature of radioactivity.
(B) Although later shown to be incomplete and partially inaccurate, Marie Curie’s investigations provided a significant step forward on the road to the eventual explanation of radioactivity.
(C) Though the scientific achievements of Marie Curie were impressive in scope, her career is blemished by her failure to determine the mechanism of radioactivity.
(D) The commitment of Marie Curie and other physicists of her time to the physicists’ model of the atom prevented them from conducting fruitful investigations into radioactivity.
(E) Although today’s theories have shown it to be inconclusive, Marie Curie’s research into the sources and nature of radioactivity helped refute the chemists’ model of the atom.

2 
 2. The passage suggests that the author would be most likely to agree with which one of the following statements about the contemporary critics of Curie’s
studies of radioactivity?

(A) The critics fail to take into account the obstacles Curie faced in dealing with the scientific community of her time.
(B) The critics do not appreciate that the eventual development of quantum mechanics depended on Curie’s conjecture that radiating substances can lose atoms.
(C) The critics are unaware of the differing conceptions of the atom held by physicists and chemists.
(D) The critics fail to appreciate the importance of the historical context in which Curie’s scientific conclusions were reached.
(E) The critics do not comprehend the intricate reasoning that Curie used in discovering polonium and radium.

3 
 3. The passage implies which one of the following with regard to the time at which Curie began studying radioactivity?

(A) Pitchblende was not known by scientists to contain any radioactive element besides uranium.
(B) Radioactivity was suspected by scientists to arise from the overall structure of pitchblende rather than from particular elements in it.
(C) Physicists and chemists had developed rival theories regarding the cause of radiation.
(D) Research was not being conducted in connection with the question of whether or not matter is composed of atoms.
(E) The majority of physicists believed uranium to be the sole source or radioactivity.

4 
 4. The author’s primary purpose in the passage is to

(A) summarize some aspects of one scientist’s work and defend it against recent criticism
(B) describe a scientific dispute and argue for the correctness of an earlier theory
(C) outline a currently accepted scientific theory and analyze the evidence that led to its acceptance
(D) explain the mechanism by which a natural phenomenon occurs and summarize the debate that gave rise to this explanation
(E) discover the antecedents of a scientific theory and argue that the theory is not a genuine advance over its forerunners

5 
 5. The primary function of the first paragraph of the passage is to

(A) narrate the progress of turn-of-the-century studies of radioactivity
(B) present a context for the conflict between physicists and chemists
(C) provide the factual background for an evaluation of Curie’s work
(D) outline the structure of the author’s central argument
(E) identify the error in Curie’s work that undermines its usefulness

6 
 6. Which one of the following most accurately expresses the meaning of the word “mechanism” as used by the author in the last sentence of the first paragraph?

(A) the physical process that underlies a phenomenon
(B) the experimental apparatus in which a phenomenon arises
(C) the procedure scientists use to bring about the occurrence of a phenomenon
(D) the isotopes of an element needed to produce a phenomenon
(E) the scientific theory describing a phenomenon

Source:   LSAT Official PrepTest 37   
 Difficulty Level:   650

RC Butler 2021  -  Practice Two RC Questions Everyday.   
Passage # 237 Date: 16-Jun-2021
 This question is a part of RC Butler 2021 .  Click here for Details

sumitkrocks · Answer

1. Which one of the following most accurately states the central idea of the passage?

(A) It is unlikely that quantum mechanics would have been developed without the theoretical contributions of Marie Curie toward an understanding of the nature of radioactivity.
 (B) Although later shown to be incomplete and partially inaccurate, Marie Curie’s investigations provided a significant step forward on the road to the eventual explanation of radioactivity. 
(C) Though the scientific achievements of Marie Curie were impressive in scope, her career is blemished by her failure to determine the mechanism of radioactivity.
(D) The commitment of Marie Curie and other physicists of her time to the physicists’ model of the atom prevented them from conducting fruitful investigations into radioactivity.
(E) Although today’s theories have shown it to be inconclusive, Marie Curie’s research into the sources and nature of radioactivity helped refute the chemists’ model of the atom.

2. The passage suggests that the author would be most likely to agree with which one of the following statements about the contemporary critics of Curie’s
studies of radioactivity?

(A) The critics fail to take into account the obstacles Curie faced in dealing with the scientific community of her time.
(B) The critics do not appreciate that the eventual development of quantum mechanics depended on Curie’s conjecture that radiating substances can lose atoms.
(C) The critics are unaware of the differing conceptions of the atom held by physicists and chemists.
 (D) The critics fail to appreciate the importance of the historical context in which Curie’s scientific conclusions were reached. 
(E) The critics do not comprehend the intricate reasoning that Curie used in discovering polonium and radium.

3. The passage implies which one of the following with regard to the time at which Curie began studying radioactivity?

(A) Pitchblende was not known by scientists to contain any radioactive element besides uranium. 
(B) Radioactivity was suspected by scientists to arise from the overall structure of pitchblende rather than from particular elements in it.
(C) Physicists and chemists had developed rival theories regarding the cause of radiation.
(D) Research was not being conducted in connection with the question of whether or not matter is composed of atoms.
(E) The majority of physicists believed uranium to be the sole source or radioactivity.

4. The author’s primary purpose in the passage is to

(A) summarize some aspects of one scientist’s work and defend it against recent criticism 
(B) describe a scientific dispute and argue for the correctness of an earlier theory
(C) outline a currently accepted scientific theory and analyze the evidence that led to its acceptance
(D) explain the mechanism by which a natural phenomenon occurs and summarize the debate that gave rise to this explanation
(E) discover the antecedents of a scientific theory and argue that the theory is not a genuine advance over its forerunners

5. The primary function of the first paragraph of the passage is to

(A) narrate the progress of turn-of-the-century studies of radioactivity
(B) present a context for the conflict between physicists and chemists
 (C) provide the factual background for an evaluation of Curie’s work 
(D) outline the structure of the author’s central argument
(E) identify the error in Curie’s work that undermines its usefulness

6. Which one of the following most accurately expresses the meaning of the word “mechanism” as used by the author in the last sentence of the first paragraph?

(A) the physical process that underlies a phenomenon 
(B) the experimental apparatus in which a phenomenon arises
(C) the procedure scientists use to bring about the occurrence of a phenomenon
(D) the isotopes of an element needed to produce a phenomenon
(E) the scientific theory describing a phenomenon

narji · Answer

Why D can't be the right option in Question5?
And how option A and C are different in Question6 to choose from?

pareshbitm · Answer

In Qs 6, Option C - states "the procedure scientists use to bring about the occurrence of a phenomenon". The decay is a natural procedure and not brought by Curie. Option A - "the physical process that underlies a phenomenon" points the right context of the word "mechanism" used in the first para.

Although I marked option E - "the scientific theory describing a phenomenon". I believe that this is also not correct for the same reaason.

pareshbitm · Answer

bm2201 
Can anyone share the OE for question 2. I marked Option A.

Talhahussaini · Answer

bm2201 
can anybody provide the explanation for question 3 please?

Sajjad1994 · Answer

Explanation

5. The primary function of the first paragraph of the passage is to

Difficulty Level:   600

Explanation

Remember that we weren’t able to identify the Main Idea in the first paragraph because it was so expository—it was a big information download that set up the playing field for the remainder of the passage.  (C), “the factual background for an evaluation of Curie’s work,”  sums this up nicely.

(A)  uses the word narrate, which doesn’t quite fit, and also is too broad. The passage deals only with Curie’s investigations.

(B)  is yet another wrong answer choice about physicists vs. chemists. There’s no  “conflict”  between the groups, and the first paragraph certainly doesn’t bear on the discussion, anyway.

We can dismiss  (D)  since we weren’t even sure of the author’s Main Idea in the first paragraph, so we can’t say that it outlines the central argument.

(E)  can be dismissed quickly, since the author of this passage would never dismiss the usefulness of Curie’s work.

Answer: C

Question #6, A and C

Reread the sentence:  “…she was unable to postulate a mechanism by which to explain radiation.”  What was Curie trying to postulate? An explanation for how radiation works. In other words,  “the physical process that underlies a phenomenon,” choice (A) .

We also know that scientists are not responsible for bringing about radiation (unless they’re setting off bombs), so  (C)  doesn’t fit here.

Hope that helps

Sajjad1994 · Answer

Explanation

2. The passage suggests that the author would be most likely to agree with which one of the following statements about the contemporary critics of Curie’s studies of radioactivity?

Difficulty Level:   700

Explanation

Paragraphs 2, 3,  and  4  all argue that Curie could not have made certain discoveries because of some very basic assumptions about matter made by the scientific community in Curie’s time. Criticisms about Curie’s understanding of radiation are thus unreasonable.  (D)  That says exactly this.

(A)  goes outside the scope of the passage, since we never see mention of obstacles in dealing with the scientific community.

(B)  again confuses why quantum mechanics is referenced in the passage—quantum mechanics led to a better understanding of the atom, which in turn led to a better understanding of radiation. The author never implies that quantum mechanics followed from the work of Curie.

The author mentions the differing conceptions of the atom held by chemists and physicists  (C)  and implies that critics fail to appreciate why this was important to Curie’s understanding, but he never intimates that critics were entirely unaware that these differing conceptions existed in the first place.

The author is debating the criticism of Curie’s understanding of the mechanism of radiation. We have no reason to believe these critics addressed Curie’s discovery of the two elements mentioned in the  first paragraph (E) .

Answer: D

Sajjad1994 · Answer

Explanation

3. The passage implies which one of the following with regard to the time at which Curie began studying radioactivity?

Difficulty Level:   750

Explanation

This question could be rather time-consuming since we have no way to research or predict an answer and the choices deal with several different areas of the passage. Luckily, we can find support for the very first answer choice—since polonium and radium are referred to as  “previously unknown” (line 10) , we can safely infer that scientists before Curie were not aware of the presence of these elements in pitchblende.

We know that even Curie was  “unable to postulate a mechanism by which to explain radiation” (lines 18-19) , so it makes no sense that the scientists before her would have specific ideas about how radiation arises  (B) .

(C)  is one of many answer choices for this passage based on an incorrect understanding of why the author discusses the theories of physicists versus chemists in Curie’s time. The author mentions the understanding of atomic structure held by each group but never makes a distinction about concepts of radiation, so we can eliminate  (C) .

Though scientists did not fully understand the atomic nature of matter, we can’t conclude that no research was being done in this area  (D) , nor can we conclude that scientists felt uranium was the only radioactive element  (E) .

Answer: A

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