To determine how much of a substance there will be after a physical change, we can refer to a fundamental concept in chemistry: the law of conservation of mass. This law states that mass is neither created nor destroyed in a physical change.
A physical change involves changes in state or appearance but does not alter the chemical composition of the substance. Examples of physical changes include melting, freezing, condensation, and vaporization. In these processes, the actual number of molecules of the substance remains the same.
Given that there are 8 grams of the substance before the physical change, this means the substance will retain its mass after the change.
Therefore, the amount of the substance after the physical change will still be 8 grams.
So, the answer is:
8 grams
