Question

the table shows the densities of four solid objects in grams per milliliter at 25°c.
object density (g/ml)
balsa wood 0.16
copper cylinder 8.94
glass bead 2.40
quartz crystal 2.65
water has a density of 1.00 gram per milliliter at 25°c. use the density values to predict which objects will float or sink when placed in water.
glass bead quartz crystal balsa wood copper cylinder
floats in water sinks in water

Explanation:

An object floats in water if its density is less than water's density ($1.00\ \text{g/mL}$), and sinks if its density is greater than water's density. Compare each object's density to $1.00\ \text{g/mL}$:

• Balsa wood: $0.16 < 1.00$, so it floats.
• Copper cylinder: $8.94 > 1.00$, so it sinks.
• Glass bead: $2.40 > 1.00$, so it sinks.
• Quartz crystal: $2.65 > 1.00$, so it sinks.

Answer:

Floats in water: balsa wood
Sinks in water: glass bead, quartz crystal, copper cylinder