Answers to Questions Kids Ask! - Where "Why?" Turns to "Wow!"
Glass has been made by humans for about 4,500 years, and it generally consists of silica (sand), potassium or soda, lime, and occasionally some other chemicals. They are melted together and cooled at air temperature so that the material is hard, but has a smooth and flowing shape, more like a liquid. The precise recipe for glass changes from place to place — the chemistry and techniques are often closely guarded secrets.
Share this Question with Your Friends!
Share This Site
Word of the Daycline:
cline: a scale of continuous gradation; continuum.
Born on this dayOctober 21, 2014
1868 - Sir Ernest Dunlop Swinton
1926 - Leonard Rossiter
1940 - Manfred Mann
1940 - Geoff Boycott
1940 - Natalia Makarova
1942 - Sir John Stevens
1954 - Eric Faulkner
1956 - Carrie Fisher
1962 - David Campese
1966 - Bjork
1971 - Jade Jagger