A large piece of iron has a density of 7.87 g/ml. What is the density of a piece of iron that is two times heavier?

Answer 1

Density is defined as mass/unit volume, i.e. mass divided by volume.

Density of a material does NOT change as the mass changes, so the density of a piece of iron that is twice as heavy (twice the mass) as another piece still has the same density, i.e. 7.87 g/ml.

Put another way, density is an INTENSIVE property, not an EXTENSIVE property.