Density is mass per unit volume. More marbles is more mass, but will be more volume as well. If the marbles are all the same, any number of them will have the same density, which is 2.5 grams/cm3. This is a "thinking" problem rather than a "calculation" problem.
float
The density is an intensive property; the density of lead remain unchanged in every piece of lead from this rod.
2.0-2.7mg/cm3
0,00045 dag/mm3.
The density of a pure sodium chloride crystal is 2,165 g/cm3.
A substance with density equal to 2.1 gcm3 it's sinking in water.
sink
float
float
about 1.1
A substance with a density of 1.3gcm-3 would sink in water. Float (APEX)
20.3g Al
The masses of each are 8.1 cm3
The density is an intensive property; the density of lead remain unchanged in every piece of lead from this rod.
2.0-2.7mg/cm3
19.3
0,00045 dag/mm3.