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3.2 Using the Periodic Table
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.
New Vocabulary to Look for… Period Group Noble gas Metal Transition element Lanthanide Actinide Nonmetal Metalloid semiconductor
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?
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.
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.
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 13-18 have the second digit of
valence electrons. 13 has 3 valence electrons 14 has 4 valence electrons Fig. 3.8 p. 98
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
Noble Gases
Halogens Greek meaning “salt former” Form salt like compounds Group 17 7 valence electrons F, Cl, Br, I
Alkali Metal Group 1 (except H) 1 valence electron Li, Na, K
Alkali Metals
Alkaline Earth Metals Group 2 2 valence electrons Be, Mg, Ca, Ba
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
Physical States and Classes of Elements
Physical States of the Elements The physical states of the elements are
show on the periodic table on p. 92-93. 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.
Gallium
Classifying Elements Elements are classified into groups
Metals Nonmetals Metalloids
Majority of elements are metals Left side and center
Nonmetals Upper right corner
Metalloids Along the boundary b/t metals and nonmetals
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.
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
Transition Elements
Transition Elements
Transition Elements
Metals Elements with the atomic numbers
58-71 and 90-103 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
Inner Transition Elements
Lanthanides First series of inner transition
elements 14 elements 58-71 Also called rare earth elements-
abundance 0.01% All have similar properties
Actinides Second series of inner transition
elements 90-103 Radioactive None beyond uranium occur in
nature Unpredictable-complex structures
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.
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
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.
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.
Valence electrons in Metals Loosely bound Free to move in the solid metal Easily lost Freedom of movement =
conductivity
Valence electrons in Nonmetals and Metalloids
Tightly held Not easily lost
Chemical Reactions and Electrons
Metals tend to lose valence electrons
Nonmetals tend to share or gain electrons
General Properties and Uses of Metals, Nonmetals and Metalloids1. Familiar Metals
Jewelry, figurines, electrical circuits2. Some Lanthanides and Actinides
Compounds of europium and ytterbium – picture tubes of TV
Neodymium – high powered lasers3. Carbon and Some Other Nonmetals
Carbon: Coal, natural gas, oil, graphite, diamonds Bromine and Iodine – halogen lamps
4. Metalloids Silicon – electronic devices
Page 106-107
Semiconductors Metalloids that do not conduct
electricity as well as metals, but better than nonmetals
Uses Television Computer Handheld electronic games Calculators
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.
Silicon (Si)
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)
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)
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
Transistors Key components in electrical
circuits, amplifying the electrical signal. npn-junction pnp-junction
Review
1. Where are the halogens, noble gases, alkali metals, alkaline earth metals, lanthanide and the actinides located? Give me an example of each?
2. What are the characteristics of a metal, nonmetal and metalloid?
3. How many valence electrons does Li have?
Using the Periodic Table