(1) In 1905 Einstein interpreted the “photoelectric effect” of light, a phenomenon that cannot be explained by the wave theory of light. (2) When a photon strikes an electron, the resulting action is analogous to the collision of billiard balls. (3) The effect of such collisions can be observed when light falling on a metal plate produces a shower of electrons. (4) Einstein deduced that light is not a continuous stream of energy but is composed of individual particles or bundles of energy, which he called photons.
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4) Although sentence 1 is placed appropriately, the rest of the paragraph above is not well organized. Which of the following reorderings of sentences 2-4 most improves the continuity of the paragraph?
A) 2, 4, 3
B) 3, 2, 4
C) 3, 4, 2
D) 4, 2, 3
My choice is (D)
I think the best answer isn't shown -- The correct order should be: 1, 4, 2, 3.
Your choice of (D) is correct. Here's an explanation of why it is the best reordering:
Sentence 1 introduces the topic of Einstein interpreting the photoelectric effect, which cannot be explained by the wave theory of light.
Sentence 4 provides the conclusion of Einstein's interpretation, stating that light is composed of particles called photons.
Sentence 2 builds on this interpretation by describing the interaction between photons and electrons as analogous to the collision of billiard balls.
Sentence 3 then provides an example of this interaction, explaining that when light falls on a metal plate, it produces a shower of electrons.
By reordering the sentences as 4, 2, 3, the paragraph flows logically from the interpretation of light as photons (sentence 4), to the analogy of photon-electron interaction (sentence 2), and finally to the observation of electron showers when light falls on a metal plate (sentence 3).
This ordering improves the continuity of the paragraph by presenting the information in a logical sequence that progresses from the interpretation to the analogy and then to the observation.