George brings you mystery liquid A. You carefully pour it into a graduated cylinder with water (D=1g/ml), mystery liquid B (D=6.1g/ml), and mystery liquid C (D=0.4g/ml) so that they don’t mix. You find that mystery liquid A forms a layer between mystery liquid B and water. Provide a specific density range mystery liquid A could have.

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.

a corroding iron, if that's one of your choices