Unit%203:%20Electrons%20in%20the%20Atom%20Intro%20to%20Electron%20Configurations

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Unit 3 Electrons in the AtomIntro to Electron
Configurations
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After today you will be able to

• Explain the organization of electrons within an
  atom
• Describe what an energy level, sublevel, and
  atomic orbital is
• Draw the shapes of each sublevel
• Predict how many electrons can be held in each
  energy level

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The Quantum Mechanical Model of electrons within
an atom says we cannot pinpoint where an electron
is, but we can get the probability of where the
electron is.

• Electron configurations show how electrons are
  distributed within an atom.

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Remember when. . . ?

• You envisioned an atom having a single center and
  rings around that center?

However that wasnt the whole truth. YOU
COULDNT HANDLE THE TRUTH! ?
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Principal Energy Levels
n3

• n1,2,3,4, etc.
• Describes the average distance of an electron
  from the nucleus
• Energy increases as you move further from the
  nucleus

n2
n1
Nucleus
e-s highest in energy
e-s lowest in energy
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Within each energy level, electrons occupy
sublevels.
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Sublevels

• Correspond to the different areas an electron can
  be located in an atom.
• Represented by a letter
• Example s, p, d, f, g, h, i, etc.

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Sublevel Types
s sublevel spherical
p sublevel dumbbell
f sublevel double clover
d sublevel clover
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Types of Sublevels in Energy Levels
Energy Level Types of Sublevels
1 1s
2 2s 2p
3 3s 3p 3d
4 4s 4p 4d 4f
5 5s 5p 5d 5f (5g)
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Atomic Orbitals

• Each sublevel is oriented differently in 3-D
  space, and each orientation is called an atomic
  orbital
• Atomic orbitals can hold only two electrons

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of Atomic Orbitals in Sublevels
Type of Sublevel of Atomic Orbitals of Electrons in sublevel
s 1 2
p 3 6
d 5 10
f 7 14
g 9 18
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Orbitals for a particular sublevel are similar in
shape, but different in orientation and size.
(See sublevel shape diagram handout.)
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of Electrons in Each Energy Level
Energy Level of Electrons in an Energy Level
1 s 2
2 s p 2 6 8
3 s p d 2 6 10 18
4 s p d f 2 6 10 14 32
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In general

• s lt p lt d lt f in energy within an energy level
• Electrons prefer to occupy the orbitals that
  require the least amount of energy