4-4 A New Approach to the Atom

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4-4 A New Approach to the Atom
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Review

• Energy is quantized ( found in specific amounts)
• Electrons have wavelike behavior
• Impossible to know electron position and
  momentum.
• Can predict the probability of electron location
• Called the Quantum-mechanical model

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Probability and Orbital

• An orbital is the region where a given electron
  is likely found.
• The density of an electron cloud is called the
  electron density.
• Higher density more likely to find electron
• Lower density less likely to find electron

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• Each orbital has specific sizes and shapes. 
• s, p, d, and f. 
• The shape of the cloud is where electrons are
  likely to be found 90 of the time.

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S orbital
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P orbital- see figure 4-26 in book
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d orbital see figure 4-27 in book
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Orbitals and Energy

• The energy levels are given the initial n, called
  the principle quantum number
• As the energy of an electron increases so does
  its principle quantum number
• n 1 has only one sublevel
• n 2 has 2 sublevels, 2s and 2p
• n 3 has three sublevels, 3s, 3p, and 3d
• 4 sublevels, 4s, 4p, 4d, and 4f

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Note 3d fills before 4p, this is what is found
in nature. The energy levels get closer together.
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• Each of the sublevels orbits can contain up to
  two electrons that travel in opposite directions
  or spins

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Electron Spin

• The spin of an electron is either clockwise or
  counter clockwise
• These spins create magnetic fields

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Summary of Energy Levels, Sublevels, and Orbitals
Principal Energy Level Sublevels Orbitals
n 1 1s 1s (one)
n 2 2s, 2p 2s (one) 2p (three)
n 3 3s, 3p, 3d 3s(one) 3p(three)3d(five)
n 4 4s, 4p, 4d, 4f 4s(one)4p(three)4d(five)4f(seven)