What happens to the density of a material if you have a larger piece of it
If you have a larger piece of a material, the density remains the same. Density is defined as the mass of a material per unit volume, so as long as the mass of the material remains the same, the density will not change.
For example, if you have a certain mass of a substance spread out over a larger volume, the density will decrease because the mass is the same but the volume has increased. Conversely, if you compress the same mass of substance into a smaller volume, the density will increase because the mass is still the same but the volume has decreased.