Spiral
Notes
Periodic Table Trends
1. Valence electrons are located in the outermost energy level (P.E.L)
2. Atomic Radius: size of atom
3. Ionization Energy (I.E.): energy required to lose 1st e- from neutral atom
4. Electron Affinity (E.A.): energy required to gain an e- to a neutral atom
(sometimes energy is given off)
5. Electronegativity (E.A.): the tendency to attract e- (a scale from 0.0 “Fr”
 4.0 “F” )
Linus Pauling developed this scale not from research
Stability of e- configuration
Least stable
Most Stable
p.1
any e- configuration
Half full S.L.
s1, p3, d5, f7
Full sublevel
s2, p6 ,d10, f14
Full outer level
s2p6 d10, f14
Important Factors for Ion Formation I.E.&E.A.
1.
+
-
Attraction or repulsion (-,-) or (+,+)
2. e- shielding: # electrons between nucleus & outer valence electrons
3. Radius: distance from nucleus; different 3 of Energy Levels
4. Most stable sublevels: full or ½ full
Coulomb’s Law  F= q1q2
d2
F = Force of attraction or repulsion
d= distance between particles
q= charge of particle
Atomic Radius (A.R.) Radius of a neutral atom = Atomic radius
1. Size of the atom – defined as ½ distance between nuclei of identical
atoms joined in a molecule (nucleus is 1/10,000 diameter of the atom)
2. A.R. decreases across the period because more (+protons nucleus) &
more electrons in the same E.L. (Group I to Group VIII in a period)
Reason: Attraction increases at same E.L. pulling atom more tightly
together
3. A.R. increases down group Trend
Reason: adding E.L. therefore valence electrons further away from the
nuclear Pull or Attraction
Decreasing across period
Increasing down family
p.2
Cl
Cl
F
Cl
p.3
H
F
Ionic Radius
1. Radius of a charged atom =Ionic Radius (charge must be specified)
Ionization Energy (I.E.)
1. I.E. opp. Trend from A.R.
Across period I.E. increases
Reason: because e- held more tightly closer to nucleus and more difficult
to remove from atom
2. I.E. decreases down the group because e- further away from nucleus
i.e. pull of attraction; easier to remove an e- from atom
3. I.E. + A  1e- + A+
A+ is a Cation +
4. The energy required to remove 1e- from an atom
p.2
 1st I.E  graph

 2nd I.E.

 3rd I.E.
p.4
Electron Affinity (E.A.)
1. Electron Affinity is an amount of energy
2. Energy added or released  Endo or Exo
3. A+ e-  Aforms an anion 4. Elements in Groups VA
Have an attraction for e-
VIA
VIIA
High E.A.
The Goal of ion formation is to reach a N.G. e- configuration
__________________________________________________
Which is larger, the Atom or the Ion?
Cl or Cl-1
 uses E.A. Energy because
__________________________________
Na or Na+1  I.E. (costs energy)
___________________________________________
p.5
Electronegativity
Ionization Energy
Atomic Radius
Metallic Character
Nonmetallic Character
Trend
s
Across Period
D
o
w
n
Summary Periodic Trends
A.R.
Greater Radius
Smaller Radius
Lower
I.E.
E.A.
E.N. scale
Greater
I.E.
E.A.
E.N. scale
p. 6