Chapter 6 Electronic Structure and the Periodic Table
c= λf λ = c/f f = c/λ c = speed of light, x 10 8 m/s λ = wavelength, m f = frequency, Hertz, Hz
Problem Microwaves have a wavelength of cm. Calculate their frequency in Hz cm = x m f = (2.998 x 10 8 m/s)/1.000 x m = x Hz
Problem Calculate the wavelength of a band on your AM radio with a frequency of 4.56 x 10 5 Hz. λ = (2.998 x 10 8 m/s)/(4.56 x 10 5 Hz) = 657 m
Wave
Energy E = hc/λ E = hf E = energy, Joules, J c = speed of sound, x 10 8 m/s h = Planck’s constant, x J*s
Problem Calculate the the energy of microwaves in Joules, using the frequency x Hz. E = hf E = (6.626 x J*s)(2.998 x Hz) = x J
Problem Calculate the energy in Joules of an AM radio wave having a wavelength of 657 m. E = hc/λ E = (6.626 x J*s)(2.998 x 10 8 m/s)/657 m = 3.0 x J
Quantum Numbers
Principle Quantum Number Symbolized by n Indicates the main energy level occupied by the electron Values are integers starting with 1
Angular Momentum Quantum Number Symbolized by l Indicates shape Values are 0, 1, 2, 3 spdf 0123
Magnetic Quantum Number Symbolized by m l Indicates the orientation of the orbital around the nucleus Values are l,…, +1, 0, -1,..., -l
Spin Quantum Number Symbolized by m s Indicates the fundamental spin states of an electron in an orbital Values are + ½ and -1/2
Review Electron Configurations Orbital Diagrams Noble Gas Configurations Periodic trends Atomic Radius Ionization Energy Electronegativty
Periodic Trends Atomic Radius Decreases across periodic table from left to right Increases down a group Ionization Energy Increases across periodic table from left to right Decreases down a group Electronegativity Increases across periodic table from left to right Decreases down a group
Ionic Radius Ionic Radii increase down a group. Cations are smaller than their corresponding atoms. Anions are larger than their corresponding atoms.
Chapter 6 Assignment Summary problem page 158 Chapter Review p , 5, 10, 30, 32, 34, 34, 38, 40