It is called Mass.
Among the physical characteristics of a matter which includes Weight, Mass, Volume, and Density the only characteristic that does not change is the mass. The mass of an object never change from place to place. All the objects have a mass and that is why there is a weight but it changes depends on the gravity. Mass don't.
This movement is known as convection or convection currents. This occurs due to the fact that warmer fluid is of lower density than colder fluid. This causes warmer fluid to rise and colder fluid to sink. This creates circulatory currents within the body of the fluid.
Answer: -
Concentration of PbI₂ = 1.5 x 10⁻³ M
PbI₂ dissociates in water as
PbI₂ ⇄ Pb²⁺ + 2 I⁻
So PbI₂ releases two times the amount of I⁻ as it's own concentration when saturated.
Thus the molar concentration of iodide ion in a saturated PbI₂ solution = [ I⁻] =
= 1.5 x 10⁻³ x 2 M
= 3 x 10⁻³ M
PbI₂ releases the same amount of Pb²⁺ as it's own concentration when saturated.
[Pb²⁺] = 1.5 x 10⁻³ M
So solubility product for PbI₂
Ksp = [Pb²⁺] x [ I⁻]²
=1.5 x 10⁻³ x (3 x 10⁻³)²
= 4.5 x 10⁻⁹
