Final answer:
The density of a marble remains the same when it is cut in half because density is a ratio of mass to volume that does not change when the quantity of material changes. The correct answer for the cut marble's density remains B. 2.4 g/cm³.
Step-by-step explanation:
If a marble with a density of 2.4 g/cm³ was cut in half, the density of each half would remain the same. Density is a property that is independent of the amount of material; it is the ratio of mass to volume for a substance. So when the marble is cut in half, both the mass and the volume are reduced by half, but the ratio of mass to volume, which is density, stays the same. Therefore, the correct answer would be B. 2.4 g/cm³.
For example, if we have a block of material with a density of 3 g/cm³, and it has a mass of 300 grams and a volume of 100 cm³, cutting this block into two equal parts would give us two blocks, each with a mass of 150 grams and a volume of 50 cm³. Each half block would maintain the original density of 3 g/cm³ because the ratio of mass to volume is 150 g/50 cm³, which simplifies back to 3 g/cm³.