Periodic Properties

1
Periodic Properties

• Trends in the periodic table of the elements

2
Atomic Radius

• ½ the distance between the nuclei of two
  identical atoms bonded together

3
Atomic Radius Trend
                                                
                   
4
Atomic Radius Trend Summary
                                                
                   
Atoms get smaller as you go across a
period. Atoms get larger as you go down a
group. Cause nuclear charge
5
Check Yourself

• Which of the following elements has the smallest
  atomic radius?
• A. Be
• B. Ca
• C. N
• D. Fe

6
Ionization Energy

• The energy required to remove an electron from a
  neutral atom
• 1st ionization energy to remove one e-
• 2nd ionization energy to remove a 2nd e-
• 3rd ionization energy to remove a 3rd e-
• And so on

7
Ionization Energy Trend Summary
Ionization energy increases as you go across a
period. Ionization energy decreases as you go
down a group. Cause nuclear charge
8
Check Yourself

• Which elements are the most reactive metals?
• Why?
• Which elements are the most reactive nonmetals?
• Why?

9
Ionic Radius

• An ion is bonded to a reference ion and the
  radius is measured

10
Ionic Radius Trend
11
Ionic Radius Trend Summary

• Cations form when elements lose e-.
• Positive ions are smaller than their parent atom.
• Anions form when elements gain e-.
• Negative ions are larger than their parent atom.
• Cause nuclear charge

12
Check Yourself

• Fill in the square with lt, gt, or .
• Ca ? Ca2 ion
• Fe2 ? Fe3

13
Electronegativity

• The ability of an element in a chemical bond to
  attract electrons. An elements need for
  another electron.
• Values of 0 (lowest) to 4 (highest) on the
  Pauling scale

14
Electronegativity Trend
.
15
Periodic Trends Summary
Atomic Radius


Ionic Radius