Transcript Quantum Mechanical Model

Quantum Mechanical Model
• Or…”Electron
Cloud Model”
• Electrons move
freely within
“clouds” (called
orbitals) not
just restricted
to orbits.
[http://www.gly.fsu.edu/%7Esalters/GLY1000/6_Minerals/Slide9.jpg]
Quantum Mechanical Model
• Atoms have
different
numbers and
shapes of
orbitals
depending on
their number of
electrons.
“s orbital”
p orbitals
d orbitals
Quantum Mechanical Model
• As the energy of
an electron
increases, so does
the quantum
number (n)
• Each principle
energy level is
also split up into
one or more
sublevels
• Chart on Pg. 145
[http://www.chemistry.mcmaster.ca/esam/Chapter_4/fig4-2.jpg]
Quantum Mechanical Model
• In each orbital,
only 2 electrons
can exist because
of electron spin
Click here for an
Atomic Orbital
Applet
Electron Orbital Diagrams
• Show which orbitals in an atom
electrons occupy.
• Arrows are used to represent the
electrons.
Electron Orbital Diagrams
• Aufbau Principle:
• Electrons must “fill” lower energy
orbitals before higher energy
orbitals.
• 1s before 2s, 2s before 2p …
Electron Orbital Diagrams
• Pauli Exclusion Principle:
Electrons in a orbital always
move in opposite directions
(spin!)
• Use up and down arrows.
Electron Orbital Diagrams
• Hund’s Rule: All orbitals of a
certain shape must be occupied
by one electron before they
can be paired.
Electron Orbital Diagrams
• Example: Carbon
Electron Orbital Diagrams
• Example: Oxygen
Orbital Diagrams provided by: [http://intro.chem.okstate.edu/1215/Lecture/Chapter11/Fri11216.gif]