Answer:
Rock
Explanation:
Let's calculate the density of each object:
Rock:
[tex]Density = \frac{mass}{volume}=\frac{8.5\ g}{4.5\ mL}=1.9\ g/mL[/tex]
Pencil:
[tex]Density = \frac{mass}{volume}=\frac{2.4\ g}{4.5\ mL}=0.53\ g/mL[/tex]
Therefore the rock is denser.