Final answer:
Accuracy refers to the closeness of a measurement to the true value; a graduated cylinder deemed the most accurate for measuring density had measurements closest to the accepted value. Precision is the consistency of measurements, while significant figures are important when reporting the results. A hydrometer measures density by buoyancy, and example calculations demonstrate the application of these concepts.
Step-by-step explanation:
In the context of a student's question about why a graduated cylinder was most accurate for measuring a substance's density, we need to differentiate between the terms 'accuracy' and 'precision.' Accuracy refers to how close a measurement is to the true or accepted value. In the experiment described, if a graduated cylinder's measurement of a liquid's volume is closest to the liquid's accepted density, then it is deemed most accurate because it closely aligns with the true density of the liquid.
The statement 'The graduated cylinder was the most accurate because it had a measurement closest to the accepted density' suggests that the option A ('Accuracy depends on proximity to accepted values') is correct. Precision, in contrast, relates to the consistency of repeated measurements. A hydrometer is used to measure the specific density based on buoyancy, and its precision might be different from its accuracy. When a 240-g rock displaces 89.0 cm³ of water, its density calculated by dividing mass by volume would be 2.95 g/cm³, showing the application of significant figures in measurements.