Question

Convert 3.00 µm² Graphene Area to m²
Original question: Suppose that, from measurements in a microscope, you determine that a certain layer of graphene covers an area of 3.00 µm². Convert this to square meters. Express the area in square meters to three significant figures.
Expert Verified Solution
Answer
The area of the graphene layer is . This result is obtained by squaring the linear conversion factor between micrometers and meters.
Explanation
Known:
- Initial Area ():
- Micro prefix ():
Find:
- Area () in square meters ()
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Identify the linear conversion factor The prefix "micro" () represents one-millionth of a unit. Therefore, there are micrometers in 1 meter, or 1 micrometer is equal to meters. A basic relationship showing that one micrometer is meters.
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Derive the area conversion factor ⚠️ This step is required on exams: When converting units of area, you must square the entire linear conversion factor. Failing to square the exponent is the most frequent source of error in dimensional analysis. Squaring both sides of the linear relationship to find the area ratio. Developing the conversion factor where becomes through the power of a power rule.
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Perform the substitution and calculation Multiply the given value by the derived conversion factor to cancel the square micrometers. Setting up the dimensional analysis calculation. The numerical result after applying the squared conversion factor.
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Unit and significant figure check The original measurement has three significant figures. Our conversion factor is exact, so the final answer must maintain three significant figures. The units cancel out, leaving . Dimensional analysis proof showing that only square meters remain.
Final Answer
The area expressed in square meters to three significant figures is:
Common Mistakes
- Forgetting to square the prefix: Students often multiply by instead of . Remember: if the unit is squared, the conversion factor must be squared ().
- Significant figure neglect: Ensure you keep the ".00" in to indicate that the measurement has a precision of three significant figures. Writing simply would be incorrect in a laboratory context.