Final answer:
To study whether the density of copper changes with temperature, a student should graph density versus temperature. As temperature increases, the volume might increase due to atomic vibrations, potentially decreasing the density. The experiment involves measuring the density at various temperatures and plotting these values.
Step-by-step explanation:
To determine whether the density of a solid cube of copper decreases as its temperature is increased without melting the cube, a student should graph density versus temperature. The density can be calculated by dividing the mass of the copper cube by its volume, and since the mass remains constant, any changes in density would be due to changes in volume as the temperature increases. As the temperature of the copper cube increases, the copper atoms will vibrate more and generally expand, potentially leading to a decrease in density if the volume increases significantly.
Materials such as copper have densities that are somewhat dependent on temperature, as indicated by the fact that the resistivity of metals like copper increases with increasing temperature, a phenomenon caused by increased atomic vibrations within the lattice structure. Thus, it's reasonable to infer that the density could also change with temperature because of these lattice expansions.
The experiment could be conducted by measuring the density of the copper cube at various temperatures, up until the point before it begins to melt, and plotting these values on a graph. The slope of the resulting line will indicate whether the density increases or decreases with temperature, answering the student's question.