10.4 Energy Levels of
Electrons
Electrons move in definite energy
levels; these are labeled 1 - 7
Sublevels in each of the
7 main energy levels
• Each level has sublevel(s)
which are probability shapes
that show where the electrons
may be at any one time. Also
known as orbitals.
S orbital can
hold up to 2
electrons
P orbital can hold up to
6 electrons
D orbital
can hold
up to 10
electrons
F orbital can hold up to
14 electrons
How do they fill?
• Aufbau chart shows how
electrons fill into the main
energy levels and the sublevels
or orbitals
Energy Levels and
Sublevels
•
•
•
•
•
•
•
1s
2s
3s
4s
5s
6s
7s
2p
3p
4p
5p
6p
7p
3d
4d
5d
6d
7d
4f
5f
6f
7f
Aufbau Diagram or Chart
•
•
•
•
•
•
•
1s
2s
3s
4s
5s
6s
7s
START HERE and follow
2p
the arrows!
3p 3d
4p 4d 4f
5p 5d 5f
6p 6d 6f
7p 7d 7f
Electron Configuration
• 4 Be
• 1s2 2s2
• 15 P
• 1s22s22p63s23p3
• 25 Mn
• 1s22s22p63s23p64s23d5
Now begin working HW
Handout #1
Q. O. D.—Show how you solved it!
_______1. The element with atomic number 53 contains
a) 53 neutrons b) 53 protons C) 26 neutrons & 27 protons d) 26 protons & 27
neutrons
108
_______2. The number of neutrons in an atom of
a) 47
b) 108
c) 155
47
Ag is
d) 61
27
_______3. The number of electrons in an ion of
a) 13
b) 10
c) 27
13
Al3+ is
d) 14
_______4. What is the relative atomic mass of boron if two stable isotopes of
boron have the following mass and abundance:
10.0129 amu (19.91%) & 11.0129 (80.09%)
a) 10.81 amu b) 10.21 amu c) 10.62 amu
d) 10.51 amu
Hund’s Rule
• Hund’s rule states that
electrons will fill a
subshell unpaired until it
cannot occupy a subshell
unpaired and has to pair.
(Applies only to p, d, and
f)
Pauli Exclusion Principle
• According to the Pauli
Exclusion Principle, states that
when two electrons must
occupy the same subshell they
will have OPPOSITE spin. One
will be symbolized by an UP
arrow and the other by a DOWN
arrow. Such as this example.
Pauli Exclusion Principle
• So they invented spin (+1/2
or -1/2) called spin up and
spin down. Has nothing to
do with the direction of the
electron--we don’ t know
how they move just where
they may be at with 90%
chance of finding it inside
the energy level and orbital
designated.
Orbital Diagrams
S orbitals get one box
P orbitals get 3 boxes (2 e- per
box)
D orbitals get 5 boxes and f gets
7
Orbital Diagrams (cont.)
• Insert electrons (using arrows
into each box according to
Hund’s and Pauli)
2 p3
Answer
• 2p3 (arrows can all point up or
down)
• Now try 4f10
Answer to
10
4f
• Arrows may point up or down if
they are in boxes individually;
however, if there are 2
electrons in a box, one must
point up and one down.
Now begin working on
the lab activity
Electron Configurations
#5.
#9.
Electrons and the
Periodic Table
History of the Table
Periodic Law
Important People
1. Mendeleev
• Mendeleev was a Russian
chemist who arranged the
known elements in vertical
columns in order of increasing
mass and noticed a pattern in
physical and chemical
properties
2. Mosley
• Mosley was a British physicist
who determined the atomic
number (number of protons) of
the atoms of elements and then
arranged the elements
according to their atomic
number.
3. Arrangement of
Periodic Table
• The current periodic table is
arranged in order of increasing
atomic number.
11. Periodic Law
• According to Mendeleev, “"The
properties of the elements are a
periodic function of their atomic
masses"
• According to Mosley, the
periodic table was arranged
according to atomic number and
patterns repeat periodically
4. Periods
• Periods of the periodic table are
the horizontal rows across
5. Groups
• Groups or Families are vertical
columns on the periodic table.
• Currently we have 18 groups. We
will use the 1-18 designations.
6. Make it into a true
statement
• Elements of the same group are
very similar.
7. Change to a True
Statement
• The characteristic properties of
the elements in a period change
from group to group.
Property Summary
Metal
Physical
State
Boiling &
Melting Point
Conductivity
Malleability
Ductile
Metalloid
Nonmetal
Property Summary
Metal
Metalloid
Nonmetal
Physical
State
Mostly Solids
(Hg
exception)
Solids
Solids, liquids
(Br), and
gases
Boiling &
Melting Point
High
Intermediate
Low
Conductivity
Good
Semiconductors
Poor
Malleability
Good
Intermediate
Poor
Ductile
Good
Intermediate
Poor
Transition Elements
• Groups 3 - 12 are also
called the Heavy Metals
Inner Transition
• Rare Earth elements that are
located in the bottom two rows
(away from the rest of the table)
of the periodic table
Groups with names
•
•
•
•
Group
Group
Group
Group
1 = Alkali Metals
2 = Alkaline Earth Metals
18 = Inert or Noble Gases
17 = Halogens
Periodic Table and
Electron Configuration
• The light metals compose the s
block.
• The transition elements are the
d block.
• The nonmetals are p block.
• The inner transition (rare earth)
metals are the f block.
Periodic Table
1
2
3
4
3
4
5
4
5
6
5
6
7
6
7
4f
5f
s block
p block
d block
f block
Noble (inert) gases
Shorthand Electron
Configuration
Using Noble Gases to
shorten the electron
configuration
•
•
•
•
•
•
•
•
Complete the electron
configurations for the
Noble Gases (Hint:
Group 18)
• Xe =
He
1s2
Ne
1s22s22p6
Ar =
1s22s22p63s23p6
Kr =
1s22s22p63s23p64s23d1
04p6
1s22s22p63s23p64s23d10
4p65s24d105p6
• Rn =
1s22s22p63s23p64s23d10
4p65s24d105p66s24f145d1
06p6 Except He, do you
see a trend in all of the
noble gas
configurations?
• What do they all end
in?
Shorthand Notation
• We use the noble gases in
shorthand notation
• Find the closest noble gas that
has an atomic number LESS
than that of the element
Example
•
•
•
•
•
•
•
•
Ex. K
What is K’s atomic number?
19
Closest noble gas?
Ar
What is Ar’s atomic number?
18 = 1s22s22p63s23p6
= [Ar] 4s1 = Means the first 18 electrons are
arranged like argon and the last electron
is called the VALENCE ELECTRON
(outermost shell)
Example for you to try
•You try Ba
2
•Ba = [Xe] 6s
•Try Pb
•Pb = [Xe] 6s24f145d106p2