Final answer:
The density of an object is calculated by dividing its mass by its volume, but the volume of the object in question is not provided. For identification, if the calculated density is close to 19.3 g/cm³, the density of gold, the object could be gold.
Step-by-step explanation:
To calculate the density of an object, divide the mass of the sample by its volume. The student mentioned an object with a mass of 280 grams without providing the volume, so we cannot calculate the density without additional information.
As for determining if the object is made of gold, the density of gold is 19.3 g/cm³. If the density of the object in question is similar to this value, one can infer that it could potentially be gold. A significant difference would suggest the object is not gold.
To provide a proper assessment, we would need the volume of the object the student found. If they could submerge the object in water in a graduated cylinder to measure the volume displacement, as suggested in the straightforward method, they could then divide the mass by the volume to find the density. If this calculated density is close to 19.3 g/cm³, the object may be gold.