To determine the density of the metal, the formula to be used is mass divided by volume.
So in our given, the mass is 25.5 g and the volume is 31.5 mL.
Convert the mL to L, since the density unit that we are going to use is g/L
31.5 mL x 0.001 L / 1 mL = 0.0315 L
So compute for the density:
Density = 25.5g / 0.0315 L = 0.80325 g/L