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 Dayindemnify:
indemnify: to compensate for damage or loss sustained.
Born on this dayJanuary 30, 2015
1900 - Martita Hunt
1913 - Percy Thrower
1930 - Gene Hackman
1937 - Vanessa Redgrave
1946 - John Bird
1951 - Phil Collins
1956 - Curtis Strange