1. 3.2 Using the Periodic Table

2. Objectives
Relate an element’s valence electron structure to its position in the periodic table.
Use the periodic table to classify an element as a metal, nonmetal, or metalloid.
Compare the properties of metals, nonmetals, and metalloids.

3. New Vocabulary to Look for…
Period
Group
Noble gas
Metal
Transition element
Lanthanide
Actinide
Nonmetal
Metalloid
semiconductor

4. Relationship of the Periodic Table to Atomic Structure
Periodic tables contain a vast array of information on the elements.
You will learn to use the periodic table to gather information about the elements and group of elements we are studying.
Modern periodic table is arranged according to increasing atomic number.
What information does the atomic number tell us?

5. Periods and Groups
The horizontal rows of the periodic table are called periods.
The vertical columns are referred to as groups.
Groups are also called families of elements.
Elements in the same group have similar properties.

6. Atomic Structure of Elements Within a Period
Each period starts with a group 1 element, which has 1 valence electron.
As you move across a period the number of valence electrons increases. Moving from 1, 2, 13, 14, 15, 16, 17, 18.
Group 1 elements have one electron at a higher energy level than the noble gas of the preceding period.

7. Atomic Structure of Elements Within a Group
The number of valence electrons can be predicted using the periodic table.
Group 1 has 1 valence electron
Group 2 has 2 valence electrons
Groups have the second digit of valence electrons.
13 has 3 valence electrons
14 has 4 valence electrons
Fig. 3.8 p. 98

8. Noble Gases Group 18 have the periodic table.
They have 8 valence electrons, except for He which only has 2
Full energy levels
Generally unreactive or inert
Ne, He, Ar

9. Noble Gases

10. Halogens Greek meaning “salt former” Form salt like compounds Group 17
7 valence electrons
F, Cl, Br, I

11. Alkali Metal
Group 1 (except H)
1 valence electron
Li, Na, K

12. Alkali Metals

13. Alkaline Earth Metals
Group 2
2 valence electrons
Be, Mg, Ca, Ba

14. Valence Electrons-Properties
Valence electrons help to determine the physical and chemical properties
Groups have similar properties b/c they have the same number of valence electrons
Fig. 3.9 p. 99 Electrons in Energy Levels-Group 16

15. Physical States and Classes of Elements

16. Physical States of the Elements
The physical states of the elements are show on the periodic table on p
Most elements are solids at room temperature
Only two are liquids. What are they? A. B.
All the gases except hydrogen are in the upper right corner of the table. List some.

17. Gallium

18. Classifying Elements Elements are classified into groups
Metals
Nonmetals
Metalloids
Majority of elements are metals
Left side and center
Upper right corner
Along the boundary b/t metals and nonmetals

19. Metals Have luster Conduct heat Good conductors of electricity
Most have high boiling pts.
Malleable
Ductile
Most are solid
Only one metal is in the liquid state.

20. Metals Most are located in Groups 1-13
Transition Elements- Elements in Group 3-12 (all metals)
Iron (Fe), nickel (Ni), Copper (Cu), Zinc (Zn)
Some of period 7 are synthetic and radioactive
The transition elements have a less predictable behavior and properties than the other metals

21. Transition Elements

22. Transition Elements

23. Transition Elements

24. Metals
Elements with the atomic numbers and are placed below the main table
If they were part of the main table it would be extremely wide
Known as the inner transition elements
Many were unknown in Mendeleev’s time

25. Inner Transition Elements

26. Lanthanides First series of inner transition elements
Also called rare earth elements- abundance 0.01%
All have similar properties

27. Actinides Second series of inner transition elements 90-103
Radioactive
None beyond uranium occur in nature
Unpredictable-complex structures

28. Nonmetals Nonmetals are abundant in nature
Oxygen and nitrogen make up 99% of our atmosphere
Carbon is found in more compounds than all the other elements combined.

29. Nonmetals Don’t conduct electricity Poor conductors of heat
Brittle when solid
Many are gases at room temp.
Solids lack luster
Melting points and boiling points are low
Table 3.5 p. 105 Properties of Metals and Nonmetals

30. Metalloids Have properties of both metals and nonmetals
Located between the metals and nonmetals
Si, Ge and As are semiconductor
Does not conduct electricity as well as a metal, but does better than a nonmetal
Si semiconductors made the computer revolution possible.

31. Atomic Structure of Metals, Metalloids and Nonmetals
Differences occur b/c of the different arrangements of electrons
Number, arrangement of valence electrons along with how tightly they are held in the atom determines the behavior.

32. Valence electrons in Metals
Loosely bound
Free to move in the solid metal
Easily lost
Freedom of movement = conductivity

33. Valence electrons in Nonmetals and Metalloids
Tightly held
Not easily lost

34. Chemical Reactions and Electrons
Metals tend to lose valence electrons
Nonmetals tend to share or gain electrons

35. General Properties and Uses of Metals, Nonmetals and Metalloids
Familiar Metals
Jewelry, figurines, electrical circuits
Some Lanthanides and Actinides
Compounds of europium and ytterbium – picture tubes of TV
Neodymium – high powered lasers
Carbon and Some Other Nonmetals
Carbon: Coal, natural gas, oil, graphite, diamonds
Bromine and Iodine – halogen lamps
Metalloids
Silicon – electronic devices
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37. Semiconductors
Metalloids that do not conduct electricity as well as metals, but better than nonmetals
Uses
Television
Computer
Handheld electronic games
Calculators

38. Semiconductors –Electrons and Electricity
An electrical current is flowing electrons.
Metals conduct electricity well because the electron are not tightly held by the nucleus and are therefore free to move.
Copper wire
At room temperature Si is not a good conductor. Its four electrons are tightly held by the nucleus.
In order to make it a good conductor it must be doped with another element.

39. Silicon (Si)

40. Doping of Si
By adding small amounts of P to Si a good conductor is created.
P has five valence electrons. This adds an extra electron which is free to move = electrical conductivity.
n-type semiconductor (negatively charged)

41. Doping of Si By adding B to Si a good conductor is created
B has three valence electrons. The shortage of electrons creates “holes” in which the electrons can move = electrical conductivity.
p-type semiconductor (positively charged)

42. Diodes The combination of n-type and p-type semiconductors is a diode.
Permits electrical flow in only one direction
Negative terminal to positive terminal

43. Transistors
Key components in electrical circuits, amplifying the electrical signal.
npn-junction
pnp-junction

44. Review
Where are the halogens, noble gases, alkali metals, alkaline earth metals, lanthanide and the actinides located? Give me an example of each?
What are the characteristics of a metal, nonmetal and metalloid?
How many valence electrons does Li have?

45. Using the Periodic Table