1.
2.
3.
4.
5.
What is a valence electron?
How many valance electrons does the
oxygen family have? The boron family?
What is the family name for group 2A?
Group 7A?
Which element is the most reactive metal?
Most reactive nonmetal?
What is the oxidation number for
members of the alkali metals family?
MODERN VIEWS OF THE ATOM
• 4 Quantum Numbers:
• Principal QN (n) refers to the energy level.
• Secondary or angular QN (l) indicates the sublevel (s, p, d,
or f)
• Sublevels:
• s = 2 e- max p = 6 e- d = 10 e- f = 14 e• Magnetic QN (ml) indicates the orbital the electron is in
• px, py or pz
• Spin QN (ms) indicates the direction the electron is spinning
(left or right)
• ½ or –½
“s” =
“p” =
SHAPE OF D
Shape of f
MIND BLOWING!!
• Just imagine an atom with for
example 92 electrons like Uranium.
All are whizzing around the nucleus
at the speed of light in different
shaped paths.
Video orbitals!
http://www.youtube.com/watch
?v=KjNgq16jEY&feature=related
THERE ARE RULES!
• Aufbau Rule: Electrons occupy the lowest energy
orbitals first.
• Hund’s Rule: States that single electrons must
occupy separate orbitals before pairing up.
• Pauli Exclusion Principle: No two electrons in an
atom have all 4 quantum numbers the same. One
quantum number must be different. Aka  SPIN!
THE “ARROW” DIAGRAM
Electrons arrange themselves in orbitals
of increasing energy.
Examples:
N
Al
K
s = 2 p = 6 d= 10 f = 14
Br
Ag
ELECTRON CONFIGURATION (LONG
FORM)
• This gives MORE information about predicting properties.
• The placement of an elements electrons is written as:
4th Energy level
6
4p
6 electrons
These add up to total
# of e-
Sublevel p
2
1s ,
2
2s ,
How many total electrons? What element is it?
6
2p ,
2
3s ,
6
3p
s Block
1
2
3
4
5
6
7
1s
2s
3s
4s
5s
6s
7s
p Block
d Block
3d
4d
5d
6d
f Block
4f
5f
2p
3p
4p
5p
6p
7p