The problem involves determining the density of a rock using the principle of volume displacement. Here's how we approach it:

• Mass of the rock (m): 63.5 g
• Volume of water displaced (V): 9.5 mL (which equals the volume of the rock)

The formula for density $\rho$ is:

$\rho = \frac{m}{V}$

Substitute the values:

$\rho = \frac{63.5 \, \text{g}}{9.5 \, \text{mL}} = 6.68 \, \text{g/mL}$

Thus, the density of the rock is 6.68 g/mL, which matches the answer in the image.

Would you like a more detailed explanation, or do you have any questions? Here are some related questions for practice:

1. What would the density be if the mass were 100 g and the displaced volume 12.5 mL?
2. How does temperature affect the volume displacement method for measuring density?
3. Can this method be used for irregularly shaped solids? Why?
4. How would you convert the density to units of kg/m³?
5. If the rock were submerged in a different liquid, how would that affect the calculation?

Tip: Always ensure your final answer reflects the correct number of significant figures based on the given data.