Transcript III. Periodic Trends

The Periodic Table
I
II
III
Chemical Reactivity
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2
3
4
5
6
7
Alkali Metals
Alkaline Earth Metals
Transition Metals
Halogens
Noble Gases
Chemical Reactivity
Period/Row
Families/Groups/Columns
Elements in the same family has the SAME # of
valence electrons
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2
3
4
5
6
7
Atomic Radius
 Atomic Radius is the distance from the nucleus to the outermost
orbital
Increases to the LEFT and DOWN
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2
3
4
5
6
7
Atomic Radius
Why larger going down?
Higher energy levels have larger orbitals
Why smaller to the right?
Increased nuclear charge
Examples
Which atom has the larger radius?
Be or Ba
Ba
Ca or Br
Ca
Ionization Energy
Ionization Energy- the energy required to
remove 1 electron from the parent atom
Why opposite of atomic radius?
In small atoms, e- are close to the nucleus
where the attraction is stronger
Ionization Energy
First Ionization Energy
Increases UP and to the RIGHT
1
2
3
4
5
6
7
Examples
Which atom has the higher 1st I.E.?
N or Bi
N
Ba
Ne
or Ne
Melting/Boiling Point
Melting/Boiling Point – the temperature
at which a substance changes states
Highest in the middle of a period.
1
2
3
4
5
6
7
Examples
Which atom has the higher
melting/boiling point?
Li or C
C
Cr or Kr
Cr
Ionic Radius
The distance between the center of the nucleus and the
outer edge of the ion
Cations/Metals
-lose elections, so they have a positive charge
-small
Atoms
-neutrally charged elements
-medium
Anions/Nonmetals
-gain electrons, so they have a negative charge
-large
Electronegativity
*The measure of how strongly an atom attracts electrons
when it is combined with another element
• Increases from left to right (except for noble gases) due
to increased nuclear charge
• Increases as you move up a group due to the shorter
distance between the nucleus and valence electrons.
Increases UP and to the RIGHT
1
2
3
4
5
6
7
Examples
Which particle has the largest
electronegativity?
S or P
S
Al or Ga
Al