[PPT]PowerPoint Presentation - Tenafly Public Schools / …sites.tenafly.k12.nj.us/~hcoyle/Chemistry...
Transcript of [PPT]PowerPoint Presentation - Tenafly Public Schools / …sites.tenafly.k12.nj.us/~hcoyle/Chemistry...
“The Elements” Song by
Tom Lehrer
• http://www.privatehand.com/flash/elements.html
Mendeleev
• Teacher at St. Petersburg University.
• Was working on a textbook for his Chemistry students.
• He organized the 63 elements known at the time.
Mendeleev’s Predictions
• He left spaces on the table for undiscovered elements.
• He predicted the properties of elements that had not yet been discovered.
• How?
Example: Eka-aluminum
• He placed this undiscovered element below aluminum.
• He predicted the melting point to be low and the density to be 5.9g/cm3.
• It was later found and named Gallium with a density of 5.91g/cm3 and melting point of 29.7oC.
A brief comparison of the modern periodic table to Mendeleev’s
• What is the main criterion used to organize elements in the modern periodic table?