Download Advanced electronic bonding and how these affect molecular shapes

Advanced electronic
configuration
Done by: Su Di Yang (8)
Introduction to advanced electrical
configuration
• Our current model of the atom no longer involves
electrons whirling through circular orbits.
• Rather, we now know we cannot pinpoint an
electron’s exact location.
• This is because of the Heisenberg uncertainty
principle. An electron cannot be pinpointed as
the photon striking it will cause it to change
momentum and position, so you will never be
able to find an exact location of an electron (until
the day you happen to find an observable particle
smaller than an electron)
Electronic configuration naming
• As we know, electrons occupy certain energy
levels around the atom.
• These energy levels are called shells.
• Electrons jump to higher energy levels when
provided with energy, but will automatically drop
back down to the lowest energy level possible.
• These energy levels are named 1, 2, 3, 4, 5, 6, 7, 8
and so on. (So far the heaviest element
discovered ever has only 7 shells of electrons)
Electronic configuration naming
(continued)
• Each of these orbitals can be further
subdivided into sub-orbitals. They have similar
energy levels but orbit the atom differently.
• So far the most common sub-orbitals are s, p,
d and f.
• So to name the possible location the atom
resides in, you state its shell number followed
by its sub-orbital number i.e. 1s,2p,3d and
stuff like that.
Number of electrons sub-orbitals can
carry
• Each sub-orbital (s, p, d and f) can hold a certain
number of electrons.
• The s sub-orbital can hold only 2 electrons
(please note from hereon the number of
electrons a sub-orbital can hold will automatically
mean the maximum number of electrons unless
stated otherwise).
• The p sub-orbital can hold 6 electrons.
• The d sub-orbital can hold 10 electrons
• The f sub-orbital can hold 14 electrons.
Number of electrons sub-orbitals can
carry (continued)
• One might notice that the number of
electrons each sub-orbital holds is always an
even number.
• This is due to the Aufbau principle and the
Pauli Exclusion principle.
Pauli Exclusion Principle
• All electrons have a property known as spin.
This spin can take the form of up or down.
• The Pauli Exclusion Principle states that no
two baryons can exist in the same quantum
state together.
• In short, two electrons with the same spin
cannot be paired together.
Aufbau Principle
• The Aufbau principle makes use of the Pauli
exclusion principle (somewhat).
• It states that each sub-orbital consists of a
number of blocks, each block can hold two
electrons (Pauli Exclusion Principle).
• That in a nutshell is why all electron suborbitals can contain an even number of
electrons.
Aufbau Principle (continued)
• The Aufbau principle also tells us the
supposed order in which the sub-orbitals are
filled up.
• To all ye fellow classmates impaired with
severe complicated-diagram-phobia, please
refrain from viewing the following slides.
Aufbau Principle
(COMPLICATED DIAGRAMS!!!!!!!!!!!!!!!!!!!!!)
Well, not really
• Provided all those with severe complicateddiagram-phobia sufferers have been
evacuated, let’s continue. 1s
2p
• Take a look at this diagram 2s
3s 3p 3d
4s 4p 4d 4f
• This diagram is all the
5s 5p 5d 5f
6p 6d 6f
sub-orbitals in seven shells. 6s
7s 7p 7d 7f
• To find the order in which the electrons are
filled, draw diagonal lines towards the bottom
left.
Aufbau principle (yes, continued again)
• One then reads down the arrows and from the
top arrow progressively to the bottom one.
• So from the previous diagram, we get
1s,2s,2p,3s,3p,4s,3d,4p,5s,4d,5s,4d,5p,6s,4f,5
d,6p,7s and so on.
• However, there are some violations of this rule
( though not enough to make it completely
useless)
The Periodic Table
• The periodic table also plays a part in
categorising sub-orbital filling as shown below:
THE END