Download Periodic Table[1]

The Periodic Table
Objectives
 Discuss how the periodic table
is organized.
 Use the periodic table to
predict atomic behavior.
 Predict characteristics of an
element based on its location.
Dmitri Mendeleev 1873
• Was trying to establish a pattern in
the 63 known elements.
• Used atomic mass, physical and
chemical properties.
• He arranged and rearranged, until
he came to this, the first periodic
table.
Periodic Law
Mendeleev’s table based on increasing
atomic mass was useful but didn’t work with
all elements.
 Modern Periodic Table is arranged according
to increasing Atomic Number
 When elements are arranged according to
increasing atomic number, there is a periodic
repetition of their physical and chemical
properties.

Modern Periodic Chart
Atomic #
Symbol
Name
Atomic Mass
6
C
Carbon
12.011
Increases in size, mass, & atomic #
Metals
Non-metals
Metals versus Non-Metals
 Metals
–good
conductors
–all solids
(ex. mercury)
 Non-metals
–poor
conductors
– solid, liquid,
gas
Main Group Elements
Main-Group Elements
 The
electron configuration of these
elements in quite consistent.
 All elements are filling the s and p
orbitals
 Chemical properties of each vertical
group or “family” are similar due to
the number of electrons in their outer
energy level.
Groups 1 & 2 “s” block
group 1:
Alkali Metals
• reactive
with water
•1 electron
in outer s
2
1
•1s 2s
Li
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
group 2:
Alkaline Earth
Metals
• less
Reactive
•2 electrons
in outer s
1s22s2
Transition Metals “d” block
Sc
Y
La
Ac
Ti
Zr
Hf
Rf
V
Nb
Ta
Db
Cr
Mo
W
Sg
Mn
Tc
Re
Bh
Fe
Ru
Os
Hs
Co
Rh
Ir
Mt
Ni Cu Zn
Pd Ag Cd
Pt Au Hg
Uun Uuu
“The Southern Island” “f” block
Lanthanides: reactive metals with
irregular electron configurations
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa
U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Actinides: so unstable that they
are radioactive.
Those Elements In Between
B
Metalloids
Al Si
“Other
Ga Ge As
Metals”
In Sn Sb Te
Tl Pb Bi Po
H
The Non-metals
He
C N O F Ne
P S Cl Ar
Se Br Kr
I Xe
At Rn
H
“Other Non-metals”
C N O
These include P S
some of the most Se
common elements
on Earth!
Halogens
•Halogen means
“salt-former”.
•Most reactive
non-metals.
•All are missing
Electron in p
Sub-level
F
Cl
Br
I
At
1s22s22p5
The Noble Gases
•Basically unreactive
because their electron
configuration is filled.
•P sublevel with 6
electrons
•For this reason, noble
gases don’t usually
bond.
He
Ne
Ar
Kr
Xe
Rn
Noble Gases are stable and un-reactive
 All
the other elements
accept or donate electrons
to attain Noble gas
electron configurations
 Although atoms of other
elements are neutral, they
lack the full outer energy
level needed to be
STABLE
So how do elements
achieve stability?
•give electrons
•take electrons
•share electrons
6.3 Periodic Trends
Atomic Radiusdefined as the distance
between nuclei of two
atoms
 Down a group radius
increases due to the
addition of higher
energy levels
 Across a period radius
actually decreases due
to the additional positive
charge of the nucleus as
protons a re added
Atomic Radius
Ions
The Loss or gain of an electron results
in the formation of a charged atom
known as an ion.
 The charge of Oxidation Number, can
be determined by comparing the
number of positive protons with
negative electrons
 Cat-ions are Positive charged ions
 An-ions are negatively charged ions

Ionization Energy



The energy needed to remove an electron from
the atom (in a gaseous state)
Ionization energy tends to decrease down a
group. Electrons in higher energy levels
become easier to remove from the atom as
they are farther from the attractive force of the
protons.
Ionization Energy increases across a period as
it becomes more difficult to remove electrons
as the energy level fills up
Ionization Energy
Electronegativity





Ability of an atom of an element to attract
electrons from another element in forming a
compound
Electronegativity values decrease from top to
bottom down a group
Tend to increase across a period from left to
right.
Noble gases do not attract electrons and
have no electronegativity
Fluorine has the highest value at 4.0, Cesium
the lowest at 0.7
Periodic trends