Download Periodic Table Organization

Unit 7:Periodic Table
Notes
Essential Question: Describe the
differences between nonmetals,
metalloids and metals.
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
Red stair step line separates metals from
nonmetals

Groups/families – vertical
↕
◦ Have similar physical and chemical properties

Periods – horizontal
↔
◦ Periods do not have similar properties
Periodic Table Organization
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Metals
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Conduct heat
Conduct electricity
Ductile
Malleable
Can be hard or soft
3 or less valence electrons
Left side of red line
Sodium
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Metalloids
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Has properties of both metals and non
metals
Touch the red line
Boron
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Nonmetals
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Does not conduct heat well
Does not conduct electricity well
Solids are brittle
Most are gases at room temperature
5 or more valence electrons
Right side of red line
Nitrogen
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The alkali metals.
These elements are metals.
 Group 1 or IA
 1 valence electron
 soft metallic solids
 Good conductors of heat and electricity
 very reactive with water to produce hydrogen gas and
lots of heat(exotherimic)
 ionize by losing their electron, so the ion has a +1
charge
 Hydrogen is not considered an alkali metal. However,
under the right conditions, hydrogen can behave like
an alkali metal.
Periodic Table Organization
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The alkaline earth metals
These elements are metals.
 Group 2 or IIA
 2 valence electrons
 metallic solids, harder than the alkali metals
 Good conductors of heat and electricity
 exothermic reaction with water.
 ionize by losing their valence electrons, so
the ion has a +2 charge
Periodic Table Organization
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The largest family of elements consist of
transition metals.
 Groups 3-12 or IB to VIIB
 valence electrons vary
 hard metallic solids
 Good conductors of heat and electricity
 dense
 high melting points
Periodic Table Organization
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The boron group.
 Group 13 or IIIA
 3 valence electrons
 diverse properties, intermediate between
those of metals and nonmetals
 best known is aluminum
Periodic Table Organization
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The carbon group.
 Group 14 or IVA
 4 valence electrons
 diverse properties, intermediate between
those of metals and nonmetals
 best known is carbon, which commonly
forms 4 bonds
Periodic Table Organization
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The nitrogen group
 Group 15 or VA
 Nitrogen Group
 5 valence electrons
 diverse properties, intermediate between
those of metals and nonmetals
 ionize by gaining 3electron, so the ion has
a -3 charge
Periodic Table Organization
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The oxygen group.
Group 16 or VIA
6 valence electrons
diverse properties, changing from
nonmetallic to metallic as you move down
the family
ionize by gaining 2 electrons, so the ion
has a -2 charge
Periodic Table Organization
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The halogen family
These are nonmetals
 Group 17 or VIIA
 7 valence electrons
 Very reactive nonmetals
 high electron affinities- attraction to
electrons
 ionize by gaining an electron, so the ion
has a -1 charge
Periodic Table Organization
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The noble gases
These are nonmetals.
 Group 18 or VIIIA
 8 valence electrons
 Do not form compounds
 stable electron octet makes these
elements unreactive under ordinary
circumstances
Periodic Table Organization
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Unit 7:Periodic Trends
Essential Question: How does atomic size
and ionization energy change across a
period and down a group?
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What influences periodic trends?
 Influenced
by three factors:
1. Energy Level
◦ Higher energy levels are further away
from the nucleus.
2. Charge on nucleus (# protons)
◦ More charge pulls electrons in closer. (+
and – attract each other)

3. Shielding effect- Outer electrons
shielded from influence of nucleus
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How is Atomic Size
determined?

Atomic radius – one half the distance
between the nuclei of two atoms of
the same element
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How does atomic size change going
across PT?
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Leaving the noble gases out, atoms get
smaller as you go across a period.
Electrons are in the same energy level.
But, there is more nuclear charge. The
electrons are pulled closer.
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How does atomic size change down a
group?
As we go down a group, each atom has
another energy level, so the atoms get
bigger.
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What is Ionization Energy?
Energy required to remove an electron
How does IE change across the PT?
 IE increase from left to right across PT
 The greater the nuclear charge, the
greater IE, because ……
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◦ All the atoms in the same period have the
same energy level.
◦ Same shielding.
◦ But, increasing nuclear charge
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Why does IE decreases down a
group?
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Greater distance from nucleus
decreases IE .
The electron is further away from the
attraction of the nucleus, and
There is more shielding.
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Essential Question:
Describe how electronegativity
changes down a group and
across a period.
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What is Electronegativity(EN)?
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the ability of an atom to attract electrons
when the atoms is in a compound
Metals have low EN
Non-metals have high EN
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How does electronegativity
change across a period?
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Electronegativity increases from left to
right across a period(Noble gases have no
EN)
Because the greater nuclear charge
attracts electrons.
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How does electronegativity
change down a group?
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EN decreases as you go down a group.
because the farther away an electrons is
from the nucleus, the more likely an atom
is to lose an e- than gain an e-.
Shielding makes it more difficult to attract
e-.
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