Final answer:
The density of the object with a mass of 12g and a volume of 143cm³ is 0.0839 g/cm³.
Step-by-step explanation:
The density of an object can be determined by dividing the object's mass by its volume. In the given question, the mass of the irregularly shaped object is 12g. To find its volume, we subtract the initial water level in the graduated cylinder (100mL) from the final water level after the object has been submerged (243mL), which calculates to 143mL or 143cm³. Hence, the density is the mass divided by the volume, which equals 12g/143cm³.
Using a calculator, the density of the object would be approximately 0.0839 g/cm³ (2 decimal places).