What is the Periodic Law?

Contributed by:
Jonathan James
The highlights are:
1. Origin of the Periodic table
2. Mendeleev's Periodic table
3. Periodic Law
4. Periods and Groups
5. Oxidation no.
6. Families of elements
7. Lanthanides and actinides
1. Periodic Law
2. SPS1. Obtain, evaluate, and communicate
information from the Periodic Table to explain
the relative properties of elements based on
patterns of atomic structure.
b.Analyze and interpret data to determine trends of
the following:
Number of valence electrons
Types of ions formed by main group elements
Location and properties of metals, nonmetals, and
Phases at room temperature
c. Use the Periodic Table as a model to predict the
above properties of main group elements.
3.  How is the periodic table
arranged?
What do elements on the same
row have in common? What do
elements in the same column
have in common?
4.  How does its location on the
 periodic table help you to
predict the peoperties of an
element?
5.  You should know the how the periodic
table is arranged
 You should know what elements on the
same rows and columns have in common
 You should know the trends of the
periodic table including
reactivity and atomic
radius change
6. Origin of the Periodic Table
 Mendeleev proposed the first arrangement
of the periodic table.
 Arranged by atomic mass
 Found that as he arranged the elements,
similar properties repeated themselves.
7. Mendeleev’s Periodic Table
8. Origin of the Periodic Table
 There were “gaps” in his table, which led
other scientists to discover new elements.
 Moseley devised the current periodic table
which is based on ATOMIC NUMBER
9. The Periodic Table
 Periodic means “repeating” pattern.
 The periodic table groups similar elements
together (think about sections in the
grocery store).
 Grouping makes it easier to predict the
properties of an element.
10. Periodic Law
 States that the repeating chemical and
physical properties of elements change
periodically with the atomic numbers of the
elements.
11. Periods
 Periods: horizontal rows of elements (7)
 Just as the number of protons changes as
you move from left to right across the
periodic table, so does the number of
electrons.
 Remember that sentences are written in rows
and end with a period.
12.
13. Groups
 Groups: Vertical column of elements on
the periodic table (18)
 Remember that group is spelled group and
groups go up and down.
 Elements in the same group have the
same number of valence electrons.
14. Groups
 Remember, valence electrons determine
an element’s properties so all elements in
the same group have similar properties.
 What makes them different then???
15.
16. Oxidation Number
 Tells how many electrons can be gained or
lost when an element reacts with other
elements.
 A positive oxidation number means it will
LOSE electrons (Ex. Sodium= +1)
 A negative oxidation number means it will
GAIN electrons (Ex. Oxygen= -2)
17. (Group 14 has + or – 4)
18. Families of Elements
 Think of each element as a member of a
family that is related to other elements
nearby.
 Elements are classified as metals,
nonmetals or metalloids
 Groups are sometimes referred to as
families
19.
20.
21. Metals
 Physical Properties: Shiny (luster), good
conductors, high density, ductile (can be
made into thin wires), malleable (can be
hammered into thin sheets) and most are
silver
 Chemical Properties: Corrosion (wearing
away because of a chemical reaction with
water), reactivity (bond with other atoms)
22.
23.
24. Types of Metals
1. Alkali Metals: very reactive
2. Alkaline-Earth Metals: form compounds
that are found in our bodies (calcium and
magnesium compounds)
3. Transition Metals: the properties
gradually change from being more similar
to Group 2 to being more like Group 13
(Gold, Silver and Platinum)
25. Nonmetals
 Physical Properties: No luster, not
conductors, brittle, not ductile, low density,
and many are gaseous (can be solids or
liquids too though)
 Chemical Properties: Highly reactive
 All, except for hydrogen, are on the right
hand side of the periodic table.
26.
27. Types of Nonmetals
1. Halogens: Group 17 (Ex. Chlorine).
Combine with most metals to form salts.
2. Noble Gases: Inert (unreactive) and do
not form with other atoms to make
compounds
28. Metalloids (Semconductors)
 Properties: shiny or dull, conductors (but
not as good as metals), ductile and
malleable
 There are only 6 total
29. Lanthanides and Actinides
 Rare earth elements
 Most of the actinides have been
synthesized by nuclear scientists (except
for uranium and thorium)
30.
31.
32. Periodic Trends Labeling Directions
1. Label the number of valence electrons at
the at the top of each group.
2. Label the oxidation number at the bottom
of each group.
33. 3. Label the following groups:
• Alkali Metals
• Alkaline Earth Metals
• Transition Metals
• Boron Group
• Carbon Group
• Nitrogen Group
• Oxygen Group
• Halogens (only group with all 3 states of matter!)
• Noble Gases
• Lanthanides
• Actinides
34. Valence electrons
Valence Electrons are:
 The electrons in the outermost shell
 Responsible for atomic bonding
 Equal to the last digit of the group number
 How many valence electrons in this atom? What
group would it be in?