November 5th, 2015
• Check Ionic Radii ws
• Understand Ionization energy trend
• Understand Electron Affinity trend
Point of Today:
1. Understand trends:
Ionization Energy
Ionization Energy: The amount of energy it takes to remove an
electron
More energy required to remove electrons from smaller atoms.
(Primary factor)
Hi g
h i o
niza
t ion
Ene
r gy
Left to Right, it takes more energy to remove electrons;
nucleus has more control.
(Secondary factor)
High Ionization Energy
e-
e-
Low energ
y to re
move
High energ
y to re
move
Sodium - Na
Francium - Fr
10 20 30 40
An atom with a large atomic size will have smaller ionization energy!
High Ionization Energy
Easiest
elect
ron to re
move
Hardest
Electro
n to re
move
Hi g
h i o
niza
t ion
Ene
r gy
Which has a larger Ionization energy…?
1. Sr or I
2. Br or Kr
It is easy to remove the first electron from Aluminum.
There are now more protons than electrons and the nucleus pulls those
remaining electrons tight. Therefore, it is hard to remove the next electron.
Now the nucleus has even a stronger hold on this electron.
It is now almost impossible to remove another electron. We have
now reached the electron configuration of a noble gas!
First Ionization Energy
• A metal is characterized by a low first ionization energy.
• An element with a high first ionization energy is a nonmetal.
Assignment
• Complete Ionization energy ws we will check in 10 minutes.