01:160:161 Chapter Notes - Chapter 4: Dmitri Mendeleev, Julius Lothar Meyer, Radius

• School: Rutgers University
• Department: Chemistry
• Course: 01:160:161
• Professor: Dr.Rabeony

Document Summary

Before: organized elements in order of increasing atomic mass. 1864 john newlands noticed that every eighth element had similar properties law of octaves: law became inadequate for the elements beyond calcium. 1869 dmitri mendeleev & lothar meyer proposed periodicity: periodicity grouped elements together more accurately, according to their properties & it made it possible to predict the properties of undiscovered elements. Main group elements elements in groups 1a through 7a (excluding noble gases because they have a completely filled p subshell, with the exception of he) Group 2b are in the d-block though. Valence electrons outermost electrons of an atom: determines how atoms interact with one another; same. Nuclear charge (z) is the number of protons in the nucleus. Effective nuclear charge (zeff) is the actual magnitude of positive charge that is experienced by an electron. Zeff = z - ; = shielding constant (0<