Ch' 5'1 Models of the Atom

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Ch. 5.1 Models of the Atom
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The Development of Atomic Models

• Rutherfords model
• Niels Bohr

• small, dense nucleus with protons, lots of empty
  space with electrons
• Electrons orbited the nucleus, didnt explain
  chemical properties

• proposed that an electron is found only in
  specific
• circular paths around the nucleus, in fixed,
  exact energy levels.

• Electrons must gain or lose exact amounts of
  energy (quantums) to change energy levels.

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Bohrs Quantum Model

• e- energy levels like the rungs on a ladder
• Electrons can move up and down the ladder rungs
• Exception rungs are not evenly spaced. The
  higher rungs (energy levels) are closer together.
• Only worked for the Hydrogen Atom

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The Quantum Mechanical Model

• Schrodinger found electrons are found in specific
  shaped clouds around the nucleus called atomic
  orbitals.
• Combines Bohrs energy levels with probability of
  an electron to be in a certain place
• Electrons are considered to be within these
  orbitals 90 of the time

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Atomic Orbitals

• Quantum energy levels are labeled by principal
  quantum numbers (n). n 1, 2, 3 etc.,
  indicating the number of sublevels it has
• Each energy sublevel corresponds to an orbital
  with a specific shape (where the electron is
  ____ of the time)
• Atomic orbitals are named s, p, d, f(specific
  order and letters!!!)

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Orbital Shapes

• s orbitals are spherical

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Orbital Shapes

• p orbitals are dumbbell-shaped
• Three different axis

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Orbital Shapes

• d-orbitals are cloverleaf shaped

• Other orbitals have even crazier shapes
• F Orbitals

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Sublevels (orbitals) of Principal Energy Levels