Final Exam Review

Extensive vs intensive properties
Extensive – Depends on amount of substance
Intensive – Does not depend on amount. (density)
Dimitri Mendeleev’s Periodic Table
Wrote elements in order of increasing mass and found a pattern of repeating properties.
Henry Mosely
Arranged elements by increasing atomic number.
Periodic Law
There is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number
Sigma and Pi Bonds
Single Bond – 1 sigma bond
Double Bond – 1 sigma, 1 pi bond
Triple Bond – 1 sigma, 2 pi bonds
Endothermic vs exothermic
Endo – Energy is absorbed in the reaction, feels cool
Exo – Energy is released by reaction, feels hot
Electronegativity Difference Values
0 – nonpolar
0 to 0.4 – mostly covalent
0.4 to 1.7 – polar covalent
greater than 1.7 – ionic