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Two chemistry students repeatedly weighed an aluminum block with a known mass of 20.00g, and obtained the following results:

Student A: 20.49g, 19.71g, 19.85g
Student B: 20.23g, 20.15g, 20.19g

(A) Student A's results are more precise and less accurate than Student B's results
(B) Student A's results are less precise and more accurate than Student B's results
(C) Student A's results are more precise and more accurate than Student B's results
(D) Student A's results are less precise and less accurate than Student B's results
(E) Student A's results are more precise and equally accurate than Student B's results

User Ovolko
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1 Answer

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Final answer:

Student A's measurements of an aluminum block are both less precise and less accurate than Student B's, as they are further from each other and the known true mass, which leads to the conclusion that option (D) is correct.

Step-by-step explanation:

To answer the student's question about the precision and accuracy of Students A and B when weighing an aluminum block, we need to understand these terms first. Precision refers to how close multiple measurements are to each other, while accuracy refers to how close those measurements are to the known true value. For Student A, the measurements are 20.49g, 19.71g, and 19.85g, and for Student B, the measurements are 20.23g, 20.15g, and 20.19g. The known true mass is 20.00g.

The data from Student B's weighings are closer to each other, indicating a higher precision. Moreover, Student B's measurements are also closer to the true value of 20.00g, indicating a higher accuracy. On the other hand, Student A's results are more spread out and less consistent, indicating lower precision. Additionally, Student A's measurements are not as close to the true value, suggesting less accuracy.

Based on the comparison of precision and accuracy, we can conclude that statement (B) is false because Student A's results are neither more precise nor more accurate. Statement (A) is also false because Student A is less precise than Student B. Considering all options, the correct statement that reflects the situation is (D), "Student A's results are less precise and less accurate than Student B's results."

User Leal
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