Download Electron Configurations Guided Notes

13 (Unit 3)
Electrons in Atoms
The chemical properties of atoms, ions, and molecules are related to the arrangement of ______________________ within them.
Over time, the atomic model has evolved regarding where __________________________ are located.
Democritus and Dalton: Atom is indivisible—no ___________________________.
Thomson’s model (Plum Pudding): described the atom as a ball of positive charge containing ___________________________
placed electrons.
Rutherford’s model: Electrons are still randomly placed, but now there's a ______________________ nucleus.
The Next Step: Max Planck's ___________________________ Energy Theory
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Energy is always absorbed or emitted in "packets" which he called _____________________.
Bohr's Model (Planetary): Bohr used quantum energy theory and proposed that electrons move in _________________________
paths with ____________________ energy in "orbits" around the nucleus.
In Bohr's Model…
 Electrons cannot exist ____________________________ energy levels, but they can move from one level to another.
o
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Think of a ladder, and the electrons can only _______________ from rung to rung.
To move from one energy level to another one, an electron must gain or lose just the __________________ amount of
energy.
o
This amount of energy is called a _______________________ of energy.
Bohr's model was only _______________________ successful.
Two other contributions led to a ______________ atomic theory.
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__________________________________________ illustrated that electrons have a ___________ nature with properties
of both particles and waves.
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_________________________________________'s Principal of Uncertainty stated that it was impossible to know both
the momentum and the _________________________ of an electron.
Modern Atomic Theory
 _____________________________'s Quantum Mechanical Model is the atomic model in use today.

It was able to explain many previously _____________________________ phenomena.
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Restricts energy of _______________________ to certain values—same as _______________.
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Does ____________ define an exact path around the nucleus—unlike _______________.
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Estimates the _______________________________ of finding an electron in a certain position (Heisenberg).
Quantum Numbers: Where is the electron??
In Schrodinger's model, there are four "quantum" numbers that tell us where an electron is __________________ to be located.
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Principal (n), 1-7 gives the _____________________level.
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Subshell (l), s-p-d-f, gives the _________________ of the region of space.
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Orbital (m), gives us the _________________________________ in space of the region.
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Spin (s): _____________________________ or counterclockwise
No 2 electrons have the same 4 _________________________ numbers.
13 (Unit 3)
Principal Quantum Number (n)
 Designates the __________________ level.

Tells how far away from the ____________________ an electron is likely to be.
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Assigned values in order of ___________________________ energy. (n = 1, 2, 3, 4, 5, 6, or 7)
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Corresponds to the _______________________ on the periodic table.

Lower value of n means the electron is __________________ to nucleus and has ____________ energy.
Subshell (l), s-p-d-f (Shapes)
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Within each principal energy level there are a certain number of ____________________________.
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Energy level 1 has 1 __________________________; level 2 has _______; level 3 has _______, etc.
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These sublevels are called _____, ______, ______, ______.
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Each sublevel has a unique _______________________.

These shapes describe the _________________ of space where an e- is likely to be located.
Orbitals (m)
 Within each sublevel there are a certain number of ________________________.

s sublevel: _____ orbital; p sublevel: _______ orbitals; d sublevel: _____ orbitals; f sublevel: _______ orbitals
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Each orbital can only hold ________ electrons.
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Orbitals within each sublevel have similar shapes, but different orientations in _________________.
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s orbitals have a ________________________________ shape.
o
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Hold a maximum of __________ electrons. First found in the __________ energy level
p orbitals have a pear or _____________________________________ shape
o
3 different ______________________________.
o
Each orientation holds a ___________ of 2 electrons.
o
The p sublevel as a whole holds a maximum of _________ electrons.
o
First found in the __________ energy level.
d-orbitals have _____________ different orientations
o
Each holds __________ electrons.
o
The d sublevel as a whole holds a __________________ of 10 electrons.
o
First found in the __________ energy level
f-orbitals do not appear until the _____________ shell (energy level) and higher.
Maximum e-s Allowed
 Max # of e-s that can occupy a principal energy level is given by the formula ____________.

How many electrons are allowed in energy level 3? __________________
Let's Review
How many orbitals are in the following sublevels?
a) 3p ________
b) 2s ________
c) 4f ________
d) 4p ________
e) 3d ________
Electron Configuration: How are the electrons in any given element _______________________________?

In an atom, electrons are positioned around the nucleus in the most _________________ arrangement possible.
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This is the arrangement that has the ______________________ energy.
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There are _____________ important rules to help us find the configuration of electrons in atoms.
Aufbau’s Principal
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Electrons will occupy orbitals having the ______________ energy first, and then in order of increasing energy.
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The _______________ state of an atom is when every e- is at its lowest energy.
Pauli’s Exclusion Principal
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An orbital can be empty, have 1 e-, or AT MOST have _______ e-s.
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Electrons occupying the same ________________ must have opposite spins—one clockwise, one counterclockwise.
Hund’s Rule
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When e-s occupy orbitals of ________________ energy, 1 e - enters each orbital until all the orbitals contain 1 e- with parallel
spins.