Transcript Periodic Table Trends - slater science

THE PERIODIC TABLE
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• Mendeleev’s
Periodic Table
(Figure 6.3)
• Arranged elements
into rows and
columns
• Elements ordered
by atomic mass.
THE PERIODIC TABLE
• Modern periodic
tables (Figure 6.5)
• Also arrange
elements into rows
and columns.
• Elements are
ordered by
increasing atomic
number
PERIODIC LAW
• There are 7 periods (rows) in the periodic
table.
• Period 1 = 2 elements
• Period 2 = 8 elements
• Period 3 = 8 elements
• Period 4 = 18 elements
• Period 5 =18 elements
• Period 6 = 32 elements
• Period 7 = 24 elements
• Each period = principal energy level.
PERIODIC LAW
• Elements within a Group (column) have
similar properties.
• The properties of elements within a period
change as you move across a period from left
to right.
• PERIODIC LAW STATES: when elements
are arranged in order of increasing atomic
number, there is a periodic repetition of
their physical and chemical properties.
Metals, Nonmetals, Metalloids
• Metals
• 80% of elements
• Good conductors of
heat and electric
current
• All are solids at
room temperature
(EXCEPT: mercury!)
• Ductile (drawn into
wires)
• Most are malleable
Metals, Nonmetals, Metalloids
• Nonmetals
• Found in the upper
right hand corner of
the periodic table
• Most are gases at
room temperature (i.e.
oxygen and nitrogen)
• Poor conductors of heat
and electric current
(except carbon)
• Solid nonmetals tend to
be brittle
Metals, Nonmetals, Metalloids
• Metalloids
• Properties similar to
both metals and
nonmetals
• Depending on the
conditions a
metalloid may
behave like a metal
or a non metal.
Checkpoint
• Which of these sets of elements have
similar physical and chemical properties?
• a. oxygen, nitrogen, carbon, boron
• b. strontium, magnesium, calcium, beryllium
• c. nitrogen, neon, nickel, niobium
• Identify each element as a metal,
metalloid, or nonmetal.
• a. gold metal
c. sulfur non metal
• b. silicon metalloid d.barium metal
Classifying Elements
• For helium, label the element symbol, element
name, atomic number and the atomic mass.
• Label all groups and periods
• Color code (entire box) with key
• Metals
• Non metals
• Metalloids
• Gas
• Liquid
• Solid
• Indicate where to find:
• Alkali metals, alkaline earth metals, halogens, noble
gases
• *** Put your name and date at the top!
The Representative Elements
• Groups IA through 7A.
• The valence electrons (electrons in the
highest occupied energy level)= group
number!
Transitional Elements
•
•
•
•
Columns 3-12 (or Groups IB-VIIIB)
Transition metals and inner transition metals
Transition metals have e- in d orbitals (main body)
Inner transition metals have e- in f orbitals (formerly
known as rare earth metals)
Practice Problems
• Use figure 6.9 and Figure 6.12 (or the
s,p,d,f handout) to write the electron
configurations of the following elements.
•
•
•
•
•
•
A. Carbon
1s2 2s2 2p2
B. Strontium
1s2 2s2 2p63s23p63d104s24p65s2
C. Vanadium
1s2 2s2 2p63s23p63d34s2
PERIODIC TRENDS
• Atomic Radius
• 1/2 the distance
between the nuclei of
two atoms of the same
element when the
atoms are joined.
• Measured in
picometers(pm)
– there are one trillion
(1012 pm in one meter)
• Decreases because #
of protons increases
therefore attractive
forces are pulling in
the e-’s .
• Increases because
you are adding more
IONS
• Ions-charged atoms
due to the gain/loss of
electrons
• Anion- ion with a
negative (-) charge
(nonmetals)
• Cation-ion with a
positive (+) charge
(metals)
• When compounds form,
elements gain or lose e’s to form ions in order
to attain a stable noble
gas configuration.
Ionization Energy
• Ionization Energy (IE)
• The amount of energy
needed or absorbed to
remove an electron
from an atom.
• The further away an ethe less IE needed to
remove the e-.( but also
consider protons and
electrons are
increasing)
IONIC SIZE
• Anions (-) are larger
than cations (+) due to
taking e-’s away which
reduces the radius.
• Among the anions and
cations the trend is the
same as atomic radius
• Decreases 
• Increases 
ELECTRONEGATIVITY
• Electronegativity
(EN)
• The ability of an
atom to attract itself
the electrons when
in a compound
(bonded).
• Electrons shift
toward the more EN
atom
PERIODIC TREND
SUMMARY
PRACTICE
• Atomic Radius--rank the following according
to size from smallest to larger.
• Mg, Al, Ca
• Al < Mg < Ca
• S, Cl, S-2
• Cl < S < S-2
• Fe +2, Fe, Fe +3
• Fe +3 < Fe +2 < Fe
PRACTICE
• Which element in each pair has a higher
electronegativity value?
• Cl or F
• F
• C or N
• N
• Mg or Ne
• Mg
• As or Ca
• As