Cupronickel is an alloy of copper with nickel containing 60-90% copper. Despite high copper content, it appears silver in color. Contains small amounts of iron and manganese for strength
Cast iron contains 2-3.5% carbon and 1-3% silicon. White iron forms cementite, grey iron has graphite flakes, ductile iron has spherical nodules. Silicon content determines whether iron forms cementite or graphite
Lead(II) oxide exists in two polymorphs: litharge (red) and massicot (yellow). Can be prepared by heating lead metal in air at 600°C. Forms naturally as rare minerals in galena ore
Original patent filed by B.F. Goodrich in 1947 for clear gun sights. Harry Coover Jr. discovered adhesive properties in 1942. Eastman Kodak developed first commercial version in 1958. Loctite gained market share in 1970s, forming Permabond
Sodium silicate is a colorless, transparent solid or white powder soluble in water. Commercial product is often greenish or blue due to iron impurities. SiO2:Na2O ratio ranges from 1:2 to 3.75:1, with lower ratios being alkaline
Natural rubber comes from isoprene polymers in rubber trees. Thailand, Malaysia, Indonesia, and Cambodia are leading producers. Trees require 250cm rainfall, 20-34°C temperature, and 80% humidity. Trees are tapped daily to collect latex from bark