How many ways can you determine density?

[MarchON]

D=m/V

I've know that there is water displacement for volume and also V=4/3πr² (object is a ball)

Is there any other way to determine density that does not involve directly finding volume?
I figure that if the object floats (and is not hollow) it is less dense than water, and if it sinks it is more dense, but can I get exact numbers from a similar method to this?

 

[Danger]

I suppose that you might be able to determine the atomic structure somehow (aside from looking it up, I mean). That should eventually lead to specific gravity.

 

[SteamKing]

D=m/V

I've know that there is water displacement for volume and also V=4/3πr² (object is a ball)

Is there any other way to determine density that does not involve directly finding volume?
I figure that if the object floats (and is not hollow) it is less dense than water, and if it sinks it is more dense, but can I get exact numbers from a similar method to this?

You haven't mentioned a problem measuring the mass of the ball. Why is measuring the volume of the ball a problem for you?

 

[Bystander]

I suppose that you might be able to determine the atomic structure somehow (aside from looking it up, I mean). That should eventually lead to specific gravity.

X-ray diffraction patterns yield internuclear spacing in lattices which can be used to calculate densities from packing fractions for lattice types and atomic masses (from mass spectrometry).