Electron Configuration
Electron Configuration
Electron Configuration
Configuration
Notes
Ground State
The lowest energy state of an atom.
Excited State
State in which an atom has a higher
potential energy then it has in its ground
state.
Heisenberg Uncertainty Principle
It is impossible to determine
simultaneously both the position and
velocity of an electron or any other
particle. (Cant exactly predict where
electrons will be, just give a general idea.)
Orbital
Three dimensional region around the
nucleus that indicates the probable
location of an electron.
Quantum Numbers
Numbers that specify the properties of
atomic orbitals and the properties of
electrons in orbitals.
l Letter
0 s
1 p
2 d
3 f
Magnetic Quantum Numbers
(m) The orientation of an orbital around
the nucleus.
Starts at l and it each integer to l
Ex. If n = 5, then l = 0, 1, 2, 3, 4,
then m = -4, -3, -2, -1, 0, 1, 2, 3, 4
Spin Quantum Number
Indicate the two fundamental spin states
of an electron in an orbital.
Can only be + or
Quantum Number Relationships in Atomic Structure
Principle
Number of
Quantum Sublevels Number of
Number of Number of Electrons
Number In Main Orbitals per
Orbitals per Electrons per Main
(Main Energy Main Energy
Sublevel per Sublevel Energy
Energy Level Level
Level
Level)
1 s 1 1 2 2
s 1 2
2 4 8
p 3 6
s 1 2
3 p 3 9 6 18
d 5 10
s 1 2
p 3 6
4 16 32
d 5 10
f 7 14
Electron Configuration
The arrangement of electrons in an atom.
Aufbau Principle
An electron occupies the lowest energy orbital that
can receive it.
Hunds Rule
Orbitals of equal energy are each occupied by one
electron before any orbital is occupied by a second
electron.
1s2
2s2
2p6
3s2
3p6
4s2
3d10
4p6
5s2
4d10
5p6
6s2
4f14
5d10
6p6
7s2
5f14
6d10
Orbital Sample 1
The electron configuration of boron is
1s22s22p1. How many electrons are
present in an atom of boron? What is the
atomic number of boron? Write the
orbital notation for boron.
Number of electrons =
super scripts added together
Number of electrons = 2 + 2 + 1
Number of electrons = 5
Nobel Gas
The group 18 elements. No unpaired
electrons and all orbitals of the energy
level are full.
E Config. Sample 1
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