cot 2 Reading the Periodic Table of elemnts and its function

its very informative

3. INTRODUCTORY ACTIVITY:
•Recall some common elements found in
the periodic table.
•Give 5 examples.

4. Ask the students:
•How was your seating arrangement
done?
•Were they arranged alphabetically?
randomly? Or other possible
arrangements?

5. Introduction to the
Periodic Table
Atomic Number ● Symbol ● Atomic Weight
Element ● Compound

6. I am Dmitri Mendeleev!
I made the PERIODIC TABLE !

7. What is the PERIODIC TABLE?
oShows all known
elements in the universe.
oOrganizes the elements
by chemical properties.

8. How do you read the
PERIODIC TABLE?

9. What is the ATOMIC NUMBER ?
oThe number of
protons found in the
nucleus of an atom
Or
oThe number of
electrons surrounding
the nucleus of an
atom.

10. What is the SYMBOL?
oAn abbreviation of
the element name.

11. What is the ATOMIC WEIGHT ?
oThe number of protons
and neutrons in the
nucleus of an atom.

12. How do I find the number of protons,
electrons, and neutrons in an element
using the periodic table?
o# of PROTONS = ATOMIC NUMBER
o# of ELECTRONS = ATOMIC NUMBER
o# of NEUTRONS = ATOMIC _ ATOMIC
WEIGHT NUMBER

15. Now you are almost as smart as I
am!
But not as handsome!
Man, I look GOOD!

16. What is an ELEMENT?
oA substance
composed of a
single kind of atom.
oCannot be broken
down into another
substance by
chemical or physical
means.

17. What is a COMPOUND?
oA substance in
which two or
more different
elements are
CHEMICALLY
bonded together.

18. Reading the Periodic Table

19. Why is the Periodic Table
important to me?
•The periodic table is
the most useful tool
to a chemist.
•You get to use it on
every test.
•It organizes lots of
information about all
the known elements.

20. Pre-Periodic Table Chemistry
…
•…was a mess!!!
•No organization of
elements.
•Imagine going to a
grocery store with no
organization!!
•Difficult to find
information.
•Chemistry didn’t make
sense.

21. Dmitri Mendeleev: Father of the
Table
HOW HIS
WORKED…
•Put elements in rows
by increasing atomic
weight.
•Put elements in
columns by the way
they reacted.
SOME PROBLEMS…
•He left blank spaces
for what he said were
undiscovered
elements. (Turned
out he was right!)
•He broke the pattern
of increasing atomic
weight to keep similar
reacting elements
together.

22. The Current Periodic Table
•Mendeleev wasn’t too far off.
•(Henry Mosley) Now the elements are put
in rows by increasing ATOMIC
NUMBER!!
•The horizontal rows are called periods and
are labeled from 1 to 7.
•The vertical columns are called groups are
labeled from 1 to 18.

23. A way of organizing & classifying
elements
•Arranged in rows and columns

25. Groups…Here’s Where the
Periodic Table Gets Useful!!
•Elements in the
same group
have similar
chemical and
physical
properties!!
•(Mendeleev did that on
purpose.)
Why??
•They have the same
number of valence
electrons.
•They will form the same
kinds of ions.

26. Families on the Periodic
Table
•Columns (groups)are
also called families.
•Families may be one
column, or several
columns put together.
•Families have names
rather than numbers.
(Just like your family
has a common last
name.)

27. Columns
•The vertical (up and
down) columns of the
periodic table (there are
18) are called groups or
families.
•Elements in the same
group or family have
similar characteristics or
properties.

28. Rows
•The horizontal rows of the periodic table are
called periods.
•Elements in a period are not alike in
properties.
•The first element in a period is usually an
active solid, and the last element in a period
is always an inactive gas.

29. Rows
•Atomic number increases from left to right
across a period.
•Atomic mass (number of protons &
neutrons) increases from left to right across
a period.

30. Rows
•Metals are on the left
•Non-metals are on the right

32. Reading the Table

33. Hydrogen
•Hydrogen belongs to a
family of its own.
•Hydrogen is a diatomic,
reactive gas.
•Hydrogen was involved
in the explosion of the
Hindenberg.
•Hydrogen is promising
as an alternative fuel
source for automobiles

34. •very reactive metals that do not occur freely in
nature
•softer than most other metals
•Explode in water
•Combine with Halogens to form salts
•Valence electrons –1
ALKALI METALSALKALI METALS

35. •metals
•very reactive
•not found free in nature
•important mineral nutrients (such as Mg and
Ca)
•Valance electrons - 2
ALKALINE EARTH ALKALINE EARTH
METALSMETALS

36. •ductile and malleable, and
conduct electricity and heat
•iron, cobalt, and nickel,
(Iron Triad) are the only
elements known to produce
a magnetic field.
TRANSITION TRANSITION
METALSMETALS

37. Transition Metals
•Elements in groups
3-12
•Less reactive harder
metals
•Includes metals used
in jewelry and
construction.
•Metals used “as
metal.”

38. RARE EARTH RARE EARTH
ELEMENTSELEMENTS
•many are man-made
•Lanthanides – soft metals that are very rare. Found in combination with Oxygen
in the Earth’s Crust
•Actinides – Radioactive, only 3 found naturals – others are man-made
(Californium used to kill cancer cells)

40. OTHER OTHER
METALSMETALS
•are ductile and malleable
•are solid, have a relatively
high density, and are
opaque

41. METALLOIDSMETALLOIDS
•have properties of both metals and non-
metals
•some of the metalloids, such as silicon and
germanium, are semi-conductors(carry an
electrical charge). This property makes
metalloids useful in computers and
calculators

42. NON-METALSNON-METALS
•not able to conduct electricity or heat very well
•very brittle, and cannot be rolled into wires or pounded into
sheets
•exist in two of the three states of matter at room temperature:
gases (such as oxygen) and solids (such as carbon).
•have no metallic luster, and do not reflect light.

43. HALOGENSHALOGENS
•"halogen" means "salt-former" and compounds
containing halogens are called "salts"
•exist in all three states of matter:
•Solid- Iodine, Astatine
•Liquid- Bromine
•Gas- Fluorine, Chlorine
•Valence Electrons - 7

44. Halogens
•Elements in group 17
•Very reactive, volatile,
diatomic, nonmetals
•Always found
combined with other
element in nature .
•Used as disinfectants
and to strengthen
teeth.

45. The Noble Gases

46. NOBLE GASESNOBLE GASES
•do not form compounds easily
VERY unreactive
Full valence (electron) shell
Used in lighted “neon” signs
Used in blimps.
Valence Electrons - 8

47. ASSESSMENT:
1.Who were the people behind the history of periodic
table? And what was their respective concept?
2.Differentiate groups from periods.
3.What are the different family names of groups found in
the periodic table?

48. Additional Activity
Why is the periodic table important?