2. One of the most important
unifying principles of Chemistry
Patterns that develop in the
elements

3. A table showing the elements and
related information about them

4. Each box in the periodic table
represents one element
▪It contains
▪Atomic Number
▪Symbol
▪Average Atomic Mass

5. Arranged in columns called groups
or families , they are organized by
the number of outer energy level/
valence electrons.

6. 18 vertical columns divided into 8-9
Groups or Families
The number of valence electrons or
the reactivity level determine which
group an element belongs to
 (In most cases the singles digit in each
group number indicates the number of
valence electrons)

7. A horizontal row of elements in The
Periodic Table.
 In most families, the reactivity of the
elements in the same family increases
as the period increases or moves down
the chart.

8. The smallest part of a compound, or
element.
A molecule must contain two or more
atoms from the Periodic Table of
Elements.
▪CO2 = Carbon Dioxide
▪CO = Carbon Monoxide
▪Au2 = Gold

9. The atoms on the periodic table
are called elements.
There are more than 110 known
elements.
▪No element with an atomic number
greater than 92 is found naturally in
measurable quantities on earth

10. Element can also refer to a pure
molecule.
That is when a molecule has only
1 element in its composition
▪O2=Oxygen
▪Au2= Gold

11. When two or more different
elements combine (bond) they
form a compound
 Examples
▪H2O = Water
▪C6H12O6= Glucose
▪CO2= Carbon Dioxide

12. Two classifications of compounds
▪Organic
▪Inorganic

13. A compound that contains a
combination of Hydrogen (H),
Carbon (C) and Oxygen (O)and
derived from a living thing
 Example
▪ Glucose C6H12O6

14.  A compound that does not contain
Carbon.
 If it does the carbon has not come
from a previously living thing
 Examples
▪ Carbon Monoxide (CO)
▪ Carbon Dioxide (CO2)
▪ Carbonates (CaCO)

17. The largest section located on the
left side of the “stair-step line” of
periodic table.

18. These elements are
▪Shiny
▪Malleable
▪Ductile
▪Conductive
▪High melting point (temperature)

19. Located to the right of the “stair-
step line” on the table.

20. These elements are:
▪Non-conductive
▪No luster or not shiny, but dull

21. Found along the stair-step line
between the metals and nonmetals.
A lot like metals but not exactly

22. Metalloids
▪Have qualities of metals and
nonmetals
▪Brittle , non-ductile and non-
malleable

23. Hydrogen & Helium
 Hydrogen
▪Classified as part of Group 1 only
because it has only 1 valence
electron.
▪However it has its own unique set of
properties that set it apart from the
other members of the group

24.  Helium
▪Classified as part of Group 8 mainly
because it has no reactivity like all of
the elements in group 8.
▪Helium has only 2 valence electrons
rather that the 8 all the other
members of this group do.

26. Dimitri Mendaleev
The “Father of the Periodic Table”,
He collected all the information
available in the nineteenth century
about the elements

27. Arranged the elements by
increasing atomic mass and found
a repeating pattern in the physical
and chemical properties

28. Eventually the table was rearranged
by atomic number as it was more
accurate that way