Question

Will every solid with the same dimensions have the same density?

Answer 1

Absolutely not...

Explanation:

And this not only applies to solids, it applies to liquids, and gases, in that the three phases will have intrinsically different densities depending on the stuff of which they are composed.

Solids and liquids are largely incompressible materials, and they have more or less constant densities, `rho="mass"/"volume"`.

Gases are compressible, and their densities are variable...