गर्मियों में खिड़कियों के कांच नीचे मोटे और ऊपर पतले क्यों हो जाते हैं?
. Due to heating during the day and cooling at night, i.e., annealing over a number of years, glass acquires some crystalline character. <br> b. Glass is not a true solid but a super cooling liquid of high viscosity (called pseudosolid). Therefore, it has the property to flow
