Question

Account for the following : 

(a) Glass objects from ancient civilizations are found to become milky inappearance. 

(b) Window glass panes of old buildings are thicker at the bottom thanat the top

Answer 1

(a)Glass objects from sncient civilizations are found to become milky because glass gets converted into crystalline solid due to heating and cooling for a long period of time. 

(b)Glass is supercooled liquid as it has tendency to flow. so, glass panes are thicker at the bottom than the top.