Question

Why does the density of solid | liquid decreases with rise in temperature? 

Answer 1

Let P = Density of solid | liquid at temperature T 

P₁ = Density of solid | liquid at Temperature T+∆T 

Since on increasing the temperature, solids | liquids expand that is their volumes increases, so by equation

i) & 2) Density is inversely proportional to volumes, so if volume increases on increasing the temperature, Density will decrease.