6 small glass beads are found to weigh 9.34 g. The beads are placed in a graduated cylinder filled with ethyl alcohol (density 0.78 g/mL). The reading of the liquid in the cylinder before the beads were added is 21.5 mL. After the beads sink to the bottom of the alcohol the reading is 24.5 mL. Calculate the density of the beads. Be sure to record your answer with the correct number of significant figures. Did it matter than alcohol rather than water is used in this experiment? Why or why not? Does it matter that this experiment was done with a collection of glass beads rather than a single solid object? Why or why not?

This is just a liquid displacement measurement.

The first thing you need to know is the volume of the beads. The volume must be the difference between the alcohol with the beads and the alcohol without them.

So, 24.5-21.5 is 3 mL.

The density of the beads is the mass divided by the volume.

We know the mass of the beads is 9.34 g and the volume is 3 mL.

So, 9.34/3 is ~ 3.11333333. Because we're using significant figures, we'll call that

3.11 g/mL.

It doesn't matter that we used alcohol because all we needed was the volume difference. Likewise, it makes no difference what shape the object (s) is/are because the displacement is the same, then the volume will be the same.