Is the following statement true? Explain fully. "Any sample made up of only one substance is homogeneous."

Consider the densities of the liquid substances listed. a) How will substance X, a solid, with density of 0.87 g/cm^3, behave when placed in each of the other pure liquids? b) Sketch and label a test tube containing substances A,B,C, and X. Assume that the liquids do not mix or react with each other and that solid Substance X does not react with any of the liquids.

(Liquid Substances; Density; Does Substance X float or sink?)
A; 0.75;??
B;1.1;??
C;0.96;??