Because an achiral molecule is symmetrical, flipping it yields a structurally identical molecule. A flipped chiral molecule, ________ can be...
GMAT Expression of Ideas : (Expression) Questions
Because an achiral molecule is symmetrical, flipping it yields a structurally identical molecule. A flipped chiral molecule, ________ can be compared to a glove that has been turned inside out: it produces a structurally inverted molecule rather than an identical one.
Which choice completes the text with the most logical transition?
in other words,
by contrast,
for example,
similarly,
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Because an achiral molecule is symmetrical, flipping it yields a structurally identical molecule." |
|
| [MISSING TRANSITION] |
|
| "A flipped chiral molecule, ______ can be compared to a glove that has been turned inside out: it produces a structurally inverted molecule rather than an identical one." |
|
Part B: Provide Passage Architecture & Core Elements
Main Point: Achiral and chiral molecules behave differently when flipped - achiral molecules remain identical while chiral molecules become inverted.
Argument Flow: The passage first establishes how achiral molecules behave when flipped (they stay identical due to symmetry), then presents how chiral molecules behave differently (they become inverted rather than identical, like a glove turned inside out).
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- Looking at our analysis, we see that achiral molecules produce identical molecules when flipped, but chiral molecules produce inverted molecules when flipped
- The sentence after the blank explicitly says chiral molecules produce "inverted molecule rather than an identical one" - this is the opposite of what happens with achiral molecules
- The transition needs to signal that we're moving from one behavior (achiral = identical) to a different behavior (chiral = inverted)
- This is a clear contrast between two different types of molecules and their opposite behaviors
- So the right answer should show contrast or opposition between what achiral molecules do versus what chiral molecules do
in other words,
"in other words,"
✗ Incorrect
- This suggests the chiral molecule information restates or clarifies the achiral molecule point
- But chiral molecules behave completely differently - they create inverted molecules, not identical ones
by contrast,
"by contrast,"
✓ Correct
- This signals that chiral molecules behave differently from achiral molecules
- Perfectly sets up the opposition: achiral produces identical vs. chiral produces inverted
- Matches our prethinking about needing to show contrasting behaviors
for example,
"for example,"
✗ Incorrect
- This would make chiral molecules an example of what was just described about achiral molecules
- But chiral molecules do the opposite - they create inverted rather than identical molecules
similarly,
"similarly,"
✗ Incorrect
- This suggests chiral molecules behave the same way as achiral molecules
- Contradicts the passage which explicitly states chiral molecules produce "inverted molecule rather than an identical one"