D. Crowley, 2007
The Periodic Table
 To recognise the periodic table, and to know what
this contains
The Periodic Table
True / False
 Elements have more than one type of atom
 Compounds are made up of two or more elements,





chemically bound
A mixture can contain both elements and
compounds
Compounds have different properties than the
elements they are made from
Mixtures are not chemically bound
All gases are compounds
There are millions of elements
False
True
True
True
True
False
False
Chemical Symbols
 What is a chemical symbol
 Can you identify any?
 Is there a pattern?
 Every element has its own chemical symbol
 It is usually one or two letters long (but can
sometimes be three)
 Every symbol begins with a capital
 The second and third letters are lower case
Symbols
 Every element has its own chemical symbol
 It is usually one or two letters long (but can sometimes be three)
 Every symbol begins with a capital
 The second and third letters are lower case
Examples
Mg
mg
MG
mG
na
NA
nA
Na
O
o
OO
oo
AG
Ag
ag
aG
Symbols
 Sometimes the symbols are really obvious: O = oxygen; Li = lithium;
Mg = magnesium
 However sometimes it is not easy to tell what the symbol stands for
(because the symbol come from a name that is not an English word)
 E.g. W stands for tungsten (from the word wolfram); Na for sodium
(from natrium)
 The chemical symbols are used all over the world, not matter what
language people speak
Periodic Table
 What is the periodic table?
 What does it show?
 How is it arranged?
Periodic Table
 All the different elements are arranged in a chart,
called the periodic table
 The elements are arranged in a special way…
Sorting
 By the middle of the 19th century about 60
elements were known
 Scientists looked for ways to sort them - most
were metals, but some were non-metals; and
most were solid, but a few were gas and some
were liquid
 However it was very difficult to find a pattern!
Mendeleev
 Then a scientist called Mendeleev did three important steps in helping
sort the elements:  He didn’t make a totally regular grid - some rows were longer than
others
 If the elements didn’t fit his table he told the original experimenters
that they must have got the mass wrong of the element!
 He left gaps for elements that he said had not been discovered yet -
and predicted what they would be like…
Periodic Table
 All the different elements are arranged in a chart the periodic table
 The elements are arranged so similar elements are
found in the vertical columns, called groups
 The horizontal rows are called periods
 The metals are on the left, the non-metals on the
right
Metals & Non-metals
 Look at the line that runs down (a bit like some
steps)
 This separates the metals and non-metals
(metals on left; non-metals on right)
Stick you periodic table into your book
Draw the ‘stairs’ to separate the metals
and non-metals
Colour the periodic table in (showing
metals versus non-metals)
Arrangement
 Similar elements are placed in groups (there are 8
different groups)
 Write these groups on your periodic table
 Note there are some gaps - these are gaps left for
undiscovered elements
Size
 The periodic table shows us one last thing
 Notice each element has its name and symbol,
e.g. oxygen (O)
 But it also has a number - e.g. Oxygen = 8
8
O
oxygen
1
12
19
47
79
82
92
103
H
Mg
K
Ag
Au
Pb
U
Lr
hydrogen
magnesium
potassium
silver
gold
lead
uranium
lawrencium
Atomic Number
 This number is the atomic number - it tells you what
element is what - e.g. oxygen always has an atomic
number of 8, magnesium always has an atomic number
of 12
 You’ll see in the table that this number gets bigger as you
go along it
1
12
19
47
79
82
92
103
H
Mg
K
Ag
Au
Pb
U
Lr
hydrogen
magnesium
potassium
silver
gold
lead
uranium
lawrencium
Summary
 Each element is made up of one type of atom only
 All elements are placed in the periodic table
 The periodic table is split between metals (left)
and non-metals (right)
 Similar elements are placed in groups (there are 8
of them)
 The rows are called periods
Bingo
 Take a mini periodic table
 If an element is said, you have to find its symbol using the big periodic
table (on the board)
 If you have that symbol on your mini periodic table you can colour in the
square
 The winner is the person who gets all their elements coloured in first…
 E.g. If I said oxygen, you would look it up, discovering its symbol is O
 If you have the O symbol on your mini periodic table then colour it in!
Periodic Table Song