This video lecture from Group IIIA and Group IVA Elements (F.Sc. second year Chemistry) covers physical properties of vitreous silica which is a glass like, amorphous form of crystalline silica. Vitreous silica is transparent, thermally stable, has lower thermal expansion, is refractory, hard, brittle, insoluble in water and wear resistant. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.