Answer:
ρ = 7.9 g/mL
Explanation:
The total volume (21.36 mL) is equal to the sum of the volume of iron and the volume of water.
V = V(water) + V(iron)
V(iron) = V - V(water)
V(iron) = 21.36 mL - 20.10 mL
V(iron) = 1.26 mL
9.9 grams of iron occupy a volume of 1.26 mL. The density (ρ) of iron is equal to its mass (m) divided by its volume (V).
ρ = m/V
ρ = 9.9 g / 1.26 mL
ρ = 7.9 g/mL
