Download Periodic Table

Find the Missing Alien
1. Study the 17 pictures of aliens.
2. Organize the pictures based on
patterns.
3. Identify and draw the missing
alien.
The Periodic Table



Development of the Periodic Table
Organization of the Periodic Table
Periodic Trends
Almost everything you see in this picture
is made up of just 7 elements.
H, O, N, C, Si, Al, Fe
Elements
 Elements cannot be broken down
by ordinary chemical processes.
 118 known elements
• 94 occur naturally
• 24 man-made
A. Development of the Periodic
Table
 Dmitri Mendeleev (1869)
• Organized elements by increasing
atomic mass.
• Grouped elements with similar
chemical and physical properties
• Predicted the existence of
undiscovered elements.
A. Development of the Periodic
Table
 Henry Mosely (1913)
• Organized elements by increasing
atomic number.
 Glen Seaborg (1940)
• Discovered transuranium elements
from 94-102
• Reordered actinide/lanthanide series
B. Organization –
Metallic Character
1
2
3
4
5
6
7
 Metals
 Nonmetals
 Metalloids
Properties of Metals and Nonmetals
Metals:
-All are solids at room
temperature (except
Hg)
-Malleable and ductile
-Lustrous
-Conduct heat and
electricity
-Typically lose electrons
when they undergo
reactions
Nonmetals:
-Usually brittle solids or
gases at room
temperature (except Br)
-Not malleable and ductile
-Non-lustrous
-Poor conductors
-Typically gain electrons
when they undergo
reactions
Properties of Metalloids
Have properties of both metals and
nonmetals:
- May be shiny or dull
- Shape is easily changed
- Typically conduct heat and
electricity better than nonmetals but
not as well as metals
- Often used as semiconductors
B. Organization –
Columns & Rows
1
2
3
4
5
6
7
 Group (Family)
 Period
B. Organization – Families
 Alkali Metals
 Alkaline Earth
1
2
3
4
5
6
7
Metals
 Transition Metals
 Halogens
 Noble Gases
Period (row)
• Each period roughly corresponds to
layer of electrons at a specific energy
level
• Each period begins with a new outer
electron orbital
• Each period ends with a completely filled
outer orbital that has the maximum
number of electrons for that orbital.
Families (columns)
• Elements in the same family have the
same number of electrons in its
outermost shell
• Elements within a family have similar
properties
C. Periodic Trends
 Periodic Law
• Properties of elements repeat
periodically when the elements
are arranged by increasing
atomic number.
C. Periodic Trend –
Atomic Radius
 Atomic Radius
• ½ the distance between bonded nuclei
• “size of the atom”
• Depends on how far the outermost
valence electrons are from the nucleus
d
C. Periodic Trends –
Atomic Radius
 Atomic Radius
• Increases to the LEFT and DOWN
1
2
3
4
5
6
7
C. Periodic Trends –
Atomic Radius
 Atomic radius decreases with
increasing atomic number across a
period.
• Increased nuclear charge (+) pulls
electrons (-) within same energy level
in more tightly.
C. Periodic Trends –
Atomic Radius
 Atomic radius increases down a
family
• Electrons at higher energy levels
have larger orbitals
• Shielding - core electrons block the
attraction between the nucleus and
the valence electrons
C. Periodic Trends –
Atomic Radius
 Which atom has the larger radius?
•Be or Ba
Ba
•Ca or Br
Ca
C. Periodic Trends –
Ionization Energy
 First Ionization Energy
• Energy required to remove the highest
energy electron from a neutral atom.
© 1998 LOGAL
C. Periodic Trends –
Ionization Energy
 First Ionization Energy
He
1st Ionization Energy (kJ)
2500
Ne
2000
Ar
1500
1000
500
Li
Na
K
0
0
5
10
Atomic Number
15
20
C. Periodic Trend –
Ionization Energy
 First ionization energy decreases down a
family.
• The highest energy electrons are farther
from the nucleus and loosely held.
 First ionization energy increases across a
period.
• Electrons experience increasing nuclear
charge with little shielding and are held
more tightly to the nucleus.
C. Periodic Trends –
Ionization Energy
 Which atom has the higher first I.E.?
•N or Bi
N
•Ba or Ne
Ne
C. Periodic Trends –
Ionization Energy
 First Ionization Energy
• Increases to the RIGHT and UP.
1
2
3
4
5
6
7
C. Periodic Trend –
Electro negativity
 Electro negativity: a relative
measure of the tendency of an
atom to attract electrons toward
itself in a chemical bond.
 The more higher the electro
negativity value, the more
strongly an atom pulls electrons
toward it.
C. Periodic Trend –
Electro negativity
•Electro negativity
•Increases to the right and up
1
2
3
4
5
6
7
C. Periodic Trend –
Electro negativity
 Electro negativity increases from left to
right across a period. As the nuclear
charge increases and the atomic radius
decreases, the increased attraction
makes it easier for atoms to attract the
electron.
 Electron negativity decreases as you
go down the group due to increasing
B. Organization – Families
 Alkali Metals
 Alkaline Earth
1
2
3
4
5
6
7
Metals
 Transition Metals
 Halogens
 Noble Gases
Reactivity of Families
 Reactivity of families
• Alkali Metals – most reactive
• Halogens – 2nd
• Alkaline earth metals – 3rd
• Noble gases – least reactive
 Reactivity increases with atomic
number within a family
Reactivity Within a Family
 http://video.google.com/videoplay
?docid=-2134266654801392897#