THE PERIODIC TABLE AND THE ELEMENTS
Mr. Broomfield
Chemistry _ CSEC
Cayman Academy
THE PERIODIC TABLE AND THE ELEMENTS
What is the periodic table ?
What information is obtained from the table ?
How can elemental properties be predicted base on the PT ?
THE PERIODIC TABLE OF
ELEMENTS
A CHART THAT ORGANIZES THE
ELEMENTS ACCORDING TO THEIR
ATOMIC NUMBER
DMITRI MENDELEEV (1869)
In 1869 Mendeleev and
Lothar Meyer (Germany)
published periodic tables
based on the similarity of
properties and reactivities
exhibited by certain elements.
Later, Henri Moseley
(England,1887-1915)
established a periodic table
based on atomic number.
Mendeleev’s Published Periodic Table of Elements
Why do you think there are question marks here?
Image taken from: http://www.chemsoc.org/networks/learnnet/periodictable/post16/develop/mendeleev.htm
Columns of elements
What are columns of elements called?
1 2
groups
3 4 5 6 7 0
Rows of elements
What are rows of elements called?
periods
1
2
3
4
5
6
7
The Periodic Table Parts
Groups
3 CLASSES OF ELEMENTS
1. Metals: to the left of the zig-zag line
2. Metalloids: border zig-zag
3. Non-metals: are to the right of zig-zag
Non-metals
Metalloids
Metals
Transition Metals
METALS
Location
Found on the left of the
zigzag line/staircase on
the periodic table
(exception  Hydrogen)
79
Au
196.967
Chemical Properties
Have few electrons in
their outer energy level,
thus lose electrons easily
11
Na
22.990
Physical Properties
ductile, good conductors,
malleable, shiny, most are
solid @ room temperature
What metal is not a solid
@ room temperature?
NON-METALS
Location
Most found to the right of
the zigzag line/staircase on
the periodic table
17
Cl
35.453
Chemical Properties
Most have almost full outer
energy levels, thus they tend
to gain electrons; some have
completely full outer level
Image taken from:
http://nobel.scas.bcit.ca/resource/ptable/cl.htm
Physical Properties
not ductile or malleable, not
shiny, poor conductors, most
are solid, but some are gas at
room temperature
16
S
32.066
Image taken from:
https://www.dmr.nd.gov/ndgs/rockandmineral/sulfur.asp
METALLOIDS
Location
Border the zigzag
line/staircase on the
periodic table
Chemical Properties
Most atoms have ½ (≈)
complete set of
electrons in outer level
Physical Properties
have properties of both
metals and non-metals
14
Si
28.086
Image taken from:
http://library.thinkquest.org/C0113863/bios.shtml
5
B
10.811
Image taken from:
http://library.thinkquest.org/C0113863/bios.shtml
Metals
Left of zig-zag
Generally <3 e’s
in outermost shell
(except Sn,Pb,Bi)
High m.p., b.p.,
density
-Most are good
conductors,
ductile, malleable
solid at room temp
(except Hg)
Metalloids
Border zig-zag
Outer shell about
½ full (3-6 e’s in
outer shell)
Non-Metals
Right of zig-zag
>5 e’s in outer
shell (Carbon has
4)
Low m.p.,
b.p.,density
Properties of both Dull, brittle, poor
metals and non- conductors
metals
More than ½ are
gases at room
temp, bromine is
liquid
Patterns: physical state
Where are elements of different states grouped in the
periodic table?
 solids
on the left, in the centre and on the right
 liquids
in the middle and on the right
 gases
on the far right (except hydrogen)
Only two elements are liquids at room temperature.
What are they?
 bromine and mercury
The Periodic Table Parts
Elements
in the
same
period
have the
same
number
of
electron
shells
Groups
Elements in the same group have
the same number of valence
electrons
GROUPS – COLUMNS OF PT
Elements in the
same group
have similar
chemical and
physical
properties!!
(Mendeleev did that on purpose.)
Why??
• They have the same
number of outer-shell
(valence) electrons.
• If the groups are
numbered 1-8 (skip
transition metals) the
group number = # e’s in
outer shell).
Groups/Families of
the Periodic Table
Alkali Metals
•Most Reactive
Metals
•Always found
bonded with other
elements
Alkaline
Earth Metals
•Very Reactive
•Always found
bonded with other
elements
Groups/Families of
the Periodic Table
Carbon Family
•Contains metals,
non-metals and
metalloids.
•Carbon is found in
all living things
Groups/Families of
the Periodic Table
Nitrogen Family
•Contains metals,
non-metals and
metalloids.
•Nitrogen is found
in the air
Groups/Families of
the Periodic Table
Oxygen Family
•Oxygen is very
reactive
•Animals breathe in
oxygen
Groups/Families of
the Periodic Table
Halogen Family
•Very Reactive
Always found
combined with other
element in nature .
Groups/Families of
the Periodic Table
Nobel Gases
•Very Stable and not
reactive
•All are found in the
air
PERIODIC TABLE: THE THREE BROAD CLASSES
MAIN, TRANSITION, RARE EARTH
Main (Representative), Transition metals, lanthanides and actinides (rare earth)
Identifying an Element Given the Group
and Period Number
Name the element found in:
group 4, period 3
1 2
1
2
group 0, period 1
group 2, period 4
Periods
group 7, period 5
3
4
5
6
7
Groups
3 4 5 6 7 0
Exam-Style Questions
Bronze:
The element magnesium has 12 electrons. State magnesium’s group
number and show
o
how you could prove your answer is correct. (2 marks).
Group 2
Exam-Style Questions
Silver:
Part of Mendeleev’s periodic table is shown below.
Group I
Group ll
Group lll
Group IV
Group V
Group VI
Group VII
Li
Be
B
C
N
O
F
Na
Mg
Al
Si
P
S
Cl
Ti
V
Group VIII
H
i.
Give the symbols of two
elements that
Mendeleev placed in
group 2 which are not
found in group 2
today.(2 marks)
o
K
Ca
Cu
Rb
Zn
Sr
Ag
Cr
As
Y
Zr
Cd
Nb
Sn
Mn
Se
Mo
Sb
In
ii.
Name these two elements. (2 marks)
iii.
Mendeleev left gaps in his periodic table. Explain why. (1 mark)
iv.
How are elements arranged in today’s periodic table? (1 mark)
I
Te
Fe Co Ni
Br
Ru Rn Pd
Q & A Exam-Style Questions
Gold:
The periodic table, as we know it today, is very different from theo early published periodic
tables. Discuss how the periodic table has changed and, where possible, name the
scientists involved. Your answer should be in chronological order.
(4 marks)
Students’ answers may vary.
•
1817, Johann Dobereiner and his Law of Triads. Placed elements into groups of 3 based
on appearance and similar reactions.
•
1864, John Newlands and his Law of Octaves. Arranged elements in order of atomic
mass and suggested that each element was similar to the element eight places further
on.
•
1869, Dmitri Mendeleev. Placed elements in order of atomic mass but left spaces for
undiscovered elements. Mendeleev wasn’t afraid to switch elements around in the
table.