Spurred by the discovery that a substance containing uranium emitted

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