Download 3.3 Electron Configuration

3.3 Electron
Configuration
Chemistry
Objectives S4:2-3
Essential Questions
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What is an electron configuration?
What are the 3 rules that govern electron
configuration and what do they mean?
What are the 3 notations and how do you write
them?
Electron Configuration
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Electron configuration is the arrangement of
electrons in an atom
Electrons are assigned quantum numbers that
work like an address of an electron
Quantum numbers specify the properties of
atomic orbitals and the properties of electrons in
orbitals.
Aufbau Principle
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Electrons enter the lowest available energy
orbital first
Pauli exclusion principle
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Each electron has its own set of four quantum
numbers
There are a maximum of 2 electrons per orbital
which means if there are two electrons in the
same orbitals they must have opposite spins
One spins clockwise, the other counter
clockwise
Hund’s Rule
For p, d, f orbitals  1 e- enters each orbital until
all contain 1 e-
Then a 2nd e- added 1 at
a time
Example: Nitrogen atomic # 7
2p
2s
1s
2p
2p
Standard notation: 1s2 2s2 2p3
Noble Gas Notation: [He] 2p3
Essential Questions



What is an electron configuration?
What are the 3 rules that govern electron
configuration and what do they mean?
What are the 3 notations and how do you write
them?
3.3 Tracked Assignments
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p 136 #10, 12-13
p 149-150 #36, 50, 68
Electron Configuration