Observing that a fire in a closed container soon went out, leading eighteenth-century scientists did not conclude that fresh air...
GMAT Expression of Ideas : (Expression) Questions
Observing that a fire in a closed container soon went out, leading eighteenth-century scientists did not conclude that fresh air (specifically, oxygen) is necessary for combustion; instead, many theorized that the container's air had become saturated with a substance called phlogiston. ________ when Joseph Priestley first isolated oxygen gas in 1774, he termed it 'dephlogisticated air.'
Which choice completes the text with the most logical transition?
In other words,
For this reason,
Alternatively,
Nevertheless,
Step 1: Decode and Map the Passage
Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Observing that a fire in a closed container soon went out, leading eighteenth-century scientists did not conclude that fresh air (specifically, oxygen) is necessary for combustion;" |
|
| "instead, many theorized that the container's air had become saturated with a substance called phlogiston." |
|
| "when Joseph Priestley first isolated oxygen gas in 1774, he termed it 'dephlogisticated air.'" |
|
Provide Passage Architecture & Core Elements
Main Point: The phlogiston theory was so influential among 18th-century scientists that it shaped how they interpreted observations and even how they named new discoveries.
Argument Flow: The passage shows how 18th-century scientists developed the incorrect phlogiston theory to explain combustion. It then demonstrates the theory's lasting influence by showing how even when oxygen was discovered, it was named in terms that reflected phlogiston thinking.
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
- The transition needs to show that Priestley's naming was a consequence of the prevailing phlogiston theory
- His choice of terminology demonstrates how deeply embedded this theory was in scientific thinking
- The right answer should indicate a cause-and-effect relationship, showing that because the phlogiston theory was dominant, Priestley named his discovery accordingly
In other words,
✗ Incorrect
- "In other words" suggests the second statement rephrases the first. But Priestley's discovery isn't restating the phlogiston theory - it's showing its influence.
For this reason,
✓ Correct
- "For this reason" establishes a clear cause-and-effect relationship. Because the phlogiston theory dominated scientific thinking, Priestley naturally named oxygen in terms that reflected that theory.
Alternatively,
✗ Incorrect
- "Alternatively" suggests Priestley's action was a different approach from the phlogiston theory. But his naming choice actually demonstrates continued thinking within the phlogiston framework.
Nevertheless,
✗ Incorrect
- "Nevertheless" indicates contrast or opposition. This would suggest Priestley's naming contradicted the phlogiston theory. But "dephlogisticated air" actually shows he was thinking in phlogiston terms.