When an iron rod is moved from the Earth to the Moon, the following properties are affected: > Mass: The mass of the rod remains unchanged regardless of its location. Mass is a measure of the amount of matter in an object and does not vary with location. > Weight: The weight of the rod will change because weight is the force due to gravity acting on the mass of the rod. Since the gravitational force on the Moon is weaker than that on Earth (about 1/6th of Earth's gravity), the weight of the rod will decrease. > Relative Density: Relative density (or specific gravity) is the ratio of the density of a substance to the density of a reference substance (usually water). Since the composition of the iron rod does not change, its relative density remains the same regardless of the location. So the properties that remain unchanged are: < Mass (i) < Relative Density (iii)