If two objects have the same mass, what must be true? choose the correct answer a. they have the same volume b. they are made of the same material c. they contain the same amount of matter d. they have the same density

Option (C) is the correct.

Explanation:

Density is known as the amount of substance present in a liter.

Mathematically,     Density =

Therefore, it means density is directly proportional to mass of a substance and inversely proportional to the volume of the substance.

Hence, density depends on both the factors, that is, mass and volume.

Whereas mass present in a substance means the amount of matter present in it.

Hence, we can conclude that if two objects have the same mass, then it is true that they contain the same amount of matter.

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".