Download Chapter 13.1 and 13.2 notes continued

Chapter 13.1 and 13.2 notes
continued
Quantum Mechanical Model of the
Atom
 Modern description of the electrons in atoms
 Doesn’t define an exact path for electrons, like the Bohr
model
 Estimates the probability of finding an electron in a defined
3D space
Atomic Orbitals
 Spaces in an atom where electrons are most likely found
 “fuzzy clouds”
 Designated by letters s, p, d and f
Shape of the Orbitals
 s orbital – spherical shaped, 1 orientation
 p orbital – dumbbell shaped, 3 orientations
 d orbital – cloverleaf shaped, 5 orientations
 f orbital – 7 orientations
http://www.youtube.com/watch?v=K-jNgq16jEY
Orbital Notation: Three Rules to Follow
 Aufbau Principle – electrons enter the lowest energy orbitals
first
 Pauli Exclusion Principle – an orbital can hold 2 electrons in
each orientation, each spinning in opposite directions
 Hund’s Rule – when electrons occupy a p, d or f orbital, one
electron enters each orientation until all contain one
electron. Then they can pair up.
Example: Chlorine
Noble gas abbreviated configuration:
 Core electrons – in the inner energy levels
 Represented by the atomic symbol of the preceding noble gas
 Valence electrons – in the outermost energy level
 Normal electron configuration for electrons after the noble gas
including the valence electrons
Example: Chlorine