SUMMERY (SUMMARY) OF ELECTRON CONFIGURATIONS

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SUMMERY (SUMMARY) OF ELECTRON CONFIGURATIONS
THE GROUND STATE CONFIGURATION 1) Given on
periodic table. 2) Inner shells are full (
except transition metals, where the last two
shells may be incomplete). 3) Most stable,
lowest energy configuration. 4) Lower shell
numbers are closest to the nucleus and are lowest
in energy level. 5) Electrons must exist in
shells, also termed energy levels and principle
quantum number. 6) The outer shell is the
valence shell and is chemically reactive, inner
shells are kernel electrons and are chemically
inactive.
11Na 2-8-1
THERE ARE TWO ELECTRONS IN SHELL N1 ( lowest
energy level in Na)
THERE IS ONE ELECTRON IN SHELL N3 VALENCE SHELL(
highest energy level here)
2-8-1
THERE ARE EIGHT ELECTRONS IN SHELL N2
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25Mn 2-8-13-2
THERE ARE TWO ELECTRON IN SHELL N4 VALENCE SHELL
THERE ARE TWO ELECTRONS IN SHELL N1
2-8-13-2
THERE ARE EIGHT ELECTRONS IN SHELL N2
THERE ARE 13 ELECTRONS IN SHELL N3, TRANSITION
METALS (GROUPS 3-12) FREQUENTLY HAVE THE OUTER
TWO SHELLS INCOMPLETE.
THIS BACKGROUND IS CORN-Y
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THE EXCITED STATE CONFIGURATION 1) Same number
of electrons as ground state, different
configuration. 2) An electron is promoted from
an inner shell (lower energy) to an outer shell
(higher energy). 3) An inner shell that is
full in the ground state will be incomplete in
the excited state. 4) The excited state is
temporary and is imediatley followed by fallback.
11Na 2-8-1
2-8-1
GROUND STATE
2-7-2
EXCITED STATE
THIS INNER SHELL IS NOT FULL (SHOULD HAVE 8
ELECTRONS) WHICH IS INDICATIVE OF AN EXCITED
STATE.
1-8-2
EXCITED STATE
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11Na 2-8-1
EXCITATION
e-
ENERGY
e-
e-
e-
n3
e-
e-
e-
e-
e-
n2
e-
e-
nuc
n1
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11Na 2-7-2
EXCITED STATE, THE ELECTRON IS IN A HIGHER ENERGY
LEVEL THAN ITS GROUD STATE POSITION.
e-
e-
e-
e-
n3
e-
e-
e-
e-
ELECTRON HOLE, THE VACATED FORMER POSITION OF THE
ELECTRON, THE n2 SHELL IS NO LONGER COMPLETE.
e-
n2
e-
e-
nuc
n1
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11Na 2-7-2
e-
DURING FALLBACK ENERGY IS RELEASED AS LIGHT
DURING FALLBACK ENERGY IS RELEASED AS LIGHT
FALLBACK
e-
e-
e-
n3
e-
e-
e-
e-
e-
n2
DURING FALLBACK THE ELECTRON BECOMES MORE STABLE
AS IT RELEASES ITS ENERGY, GOES BACK TO GROUND
STATE.
e-
e-
nuc
n1
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11Na 2-8-1
e-
e-
e-
e-
e-
e-
n3
e-
e-
e-
n2
e-
e-
nuc
n1
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INCREASING ENERGY
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U DO IT NOW!
For the following configuration 2-8-18-6 a)
Identify the element. b) Propose an excited
state. c) How many electrons are in the
valence shell?
Simply add the electrons, which equal protons in
a neutral atom, the atomic number. 2-8-18-6
28186 34 electrons indicates an atomic
number of 34, which is Se
Write a configuration with the same number of
electrons as the ground state , but with a
different configuration. 2-8-18-6(ground)
2-8-17-7 (excited) ?NOTE electrons furthest
from the nucleus are most likely to be excited
(promoted).
2-8-18-6, 6 valence electrons (and 2818 26
kernel)