Adilute, aqueous potassium nitrate solution is best classified as a
(1) homogeneous compound
(2) homogeneous mixture
(3) heterogeneous compound
(4) heterogeneous mixture

Since aqueous means that it is a combination of water and potassuim, the answer is 2) Homogenous mixture.

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water