Transcript Chapter 5: The Periodic Table

Chapter 5:
The Periodic Table
5.2 The Modern Periodic Table
5.3 Representative groups
Section 5.2
The Modern Periodic
Table
The Modern Periodic Table

“Periodic” - Repeating patterns
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Listed in order of increasing number of
protons (atomic #)
Properties of elements repeat
Periodic Law- when elements arranged by
increasing number of protons, properties
repeat in pattern
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Columns in the Periodic Table
-vertical (up & down)
-called groups or families
-#ed 1-18 or 1A through 8A
-elements in same family have
similar properties
Rows in the Periodic Table
-horizontal (left – right)
-called a period
-properties change greatly across period
-first element in period is very active
metal
-last element in most periods is noble gas
-7 periods (number them on your
periodic table)
Element Key
Important information about an
element is given in each square
of the periodic table:
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its atomic number
chemical symbol
element name
average atomic mass
For example:
Carbon has atomic # 6
(or has 6 protons), an
average atomic mass of
12.01 and a symbol of C
6
C
Carbon
12.01
Atomic Mass
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Atomic mass is a value that depends on
the masses of an element’s isotopes and
how common they are in nature.
Two isotopes of copper
 72% copper-63
 28% copper-65
Makes the average 63.56 amu
Determining Average Atomic
Mass
Copper-63 (mass is 63) is 72% abundant
Copper-65 (mass is 65) is 28% abundant
1. Convert percent to a decimal (move decimal 2
places left)
2. Multiply decimal by the mass
3. Add the two together
4. 63*0.72 = 45.36
65*0.28 = 18.2
5. 45.36 + 18.2 = 63.5 average atomic mass
Metals
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Most solids (Hg is liquid)
Luster – shiny.
Ductile – drawn into thin
wires.
Malleable – hammered into
sheets.
Conductors of heat and
electricity.
Include transition metals –
“bridge” between elements
on left & right of table
Non-Metals
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Properties are generally opposite of
metals
Poor conductors of heat and
electricity
Low boiling points
Many are gases at room temperature
Solid, non-metals are brittle (break
easily)
Chemical properties vary
Metalloids
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stair-step pattern
Have properties similar to
metals and non-metals
Ability to conduct heat and
electricity varies with temp

Better than non-metals but
not metals
Variation Across a Period:
Left to Right
Physical and Chemical properties
 Atomic size decreases
 Metallic properties decrease
 Ability to lose an electron decreases
 Ability to gain electrons increases

Section 5.3
Representative Groups
Hip Hop Classroom
The Elements
What are Valence electrons?
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outermost e-’s
Responsible for chem props
Elements in same group…
same # of VE
ALL atoms want full outer
energy level (usually 8 VE)
To get full outer energy level, some
elements:
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lose e- (metals)
gain e- (non-metals)
share electrons (some non-metals & metalloids)
Introducing the
ten major
groups
(families) on the
modern
Periodic Table:
Alkali Metals
reactivity increases
- 1 valence electron (VE)
- soft, silver-white, shiny
metals
- never found pure
- most reactive metals
- Reactivity increases
down group
potassium
Label the Alkali Metals to your PT
Alkaline Earth Metals
- 2 VE
- not as reactive as
alkali metals
- often mixed with Al
-
forms strong/light
weight alloys
magnesium
Alkaline Earth Metals
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Magnesium
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Used to make steel
(light metal w/o
losing strength)
photosynthesis
(chlorophyll)
Calcium
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bones & teeth
Chalk, limestone,
pearls, plaster
Label the Alkaline Earth Metals to
your PT
Boron Family
-3 VE
Boron
 Hard/brittle
 never found pure
in nature
 in borax...used to
make detergents
& cosmetics
Boron Family
Aluminum
 most
abundant
metal in
earth’s crust
 important
metal for
industry
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light, strong,
slow to
corrode
Aluminum
13
Al
Aluminum
26.98
Label the Boron Family on
your PT
silicon
Carbon Family
-
-
4 VE
Can gain 4 e-, lose
4 e-, or share eMost compounds
in body contain C
Si 2nd most
abundant element
in Earth’s crust
Si used to tip saw
blades
Label the Carbon Family on
your PT
Nitrogen Family
-
-
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5 VE
Tend to gain 3 eN and P used in
fertilizers
P on tips of matches
Arsenic
Label the Nitrogen Family on
your PT
Oxygen Family
-
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6 VE
Tend to gain 2 eO very abundant element
S used in fertilizers
O needed for digestion
sulfur
Label the Oxygen Family on
your PT
Halogen Family (“salt-former”)
-7 VE
-most active nonmetals
-never found pure in nature
-react with alkali metals easily
(forms salts)
-F most active halogen
Halogens cont…
F
compounds in toothpaste
 Cl kills bacteria
 I keeps thyroid gland working
properly
bromine
Label the Halogen Group on your Periodic Table
The Noble Gases (Inert Gases)
- non-reactive
- outermost e- shell is
full (8 VE)
- In “neon” lights
-in earth’s
atmosphere (less
than 1%)
Neon
Label the Noble Gases on your Periodic Table
Transition Metals
mercury
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Almost all solids at room temp (Hg exception)
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ductile, malleable, conductors
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VE varies
Less Reactive than Groups 1 & 2
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Fe, Co, and Ni produce magnetic field
Label the Transition Metals on your periodic table
uranium
Rare Earth Elements
Lanthanide series (period 6)
 Actinide Series (period 7)
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Some radioactive
Separated from table to make easy to
read/print
silver, silvery-white, or gray metals.
Conduct electricity
Label the Lanthanide Series on
your PT
Label the Actinide Series on
your PT
You may watch more videos about the
elements at:
http://www.periodicvideos.com/
or sing along at:
http://www.youtube.com/watch?v=zGM-wSKFBpo&feature=related
elemental funkiness - Mark Rosengarten
hip hop classroom