The document is about the periodic table and the arrangement of elements within it. It discusses how Dmitri Mendeleev created the first modern periodic table by arranging elements in order of atomic number, which led to patterns in their properties. Elements are arranged in the periodic table based on their atomic structure, with each element having a unique number of protons and electrons equal to its atomic position. The position of an element reflects trends in how its outer electron shells are filled and its chemical and physical properties.

1. © Boardworks Ltd 2007
1 of 44

2. 2 of 44 © Boardworks Ltd 2007

3. © Boardworks Ltd 2007
3 of 44
What is the periodic table?
Mendeleev created the first modern periodic table.
What does it show and why is it always in the same order?

4. © Boardworks Ltd 2007
4 of 44
What is an element?

5. © Boardworks Ltd 2007
5 of 44
Where were the elements made?
There are 92 naturally-occurring elements and about 15
artificially-produced elements.
Elements were originally made in
stars. In the early stages of a star’s
life, light elements, such as
hydrogen and helium, are formed.
These fused together to make
heavier elements such as carbon.
Some of the even heavier elements
were produced deep within stars
and were sent out into the Universe
when the stars exploded.
Most of the artificially-produced elements have only been
made in nuclear reactors or particle accelerators.

6. © Boardworks Ltd 2007
6 of 44
What are elements made of?
Each element is made up of one type of atom, which is
different to the atoms in any other element.
Gold is an
element made up
of only gold atoms.
Carbon is an
element made up
of only carbon atoms.
Oxygen is an
element made up
of only oxygen atoms.

7. © Boardworks Ltd 2007
7 of 44
What are atoms made of?

8. © Boardworks Ltd 2007
8 of 44
What is the atomic number?
Every element has a unique atomic number. This is the
number of protons in the nucleus of each atom.
What is the atomic number of
this helium atom?
A neutral atom must have equal numbers of protons and
electrons, so the atomic number of an element also gives
the number of electrons.
Helium has 2 protons, so its
atomic number is 2.
Atoms are neutrally charged,
so what links atomic number
and the number of electrons?
electron
proton
neutron

9. © Boardworks Ltd 2007
9 of 44
What are the properties of elements?
A property is any characteristic feature of a substance.
Properties of sodium include:
The chemical properties of an element are
determined by its atomic number.
Are there any patterns in the properties of the elements?
 highly reactive
 solid but melts easily
 feels light (low density).
Can you name any properties
of the element sodium?
A property is any characteristic feature of a substance.

10. © Boardworks Ltd 2007
10 of 44
Elements and atoms – true or false?

11. 11 of 44 © Boardworks Ltd 2007

12. © Boardworks Ltd 2007
12 of 44
How was the periodic table developed?

13. © Boardworks Ltd 2007
13 of 44
How are the elements arranged?

14. © Boardworks Ltd 2007
14 of 44
The periodic table
Arranging all the elements by their atomic number and their
properties led to the creation of…
…the periodic table
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg ? ? ? ? ? ? ?
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Na Mg Al Si P S Cl Ar
Li Be B C N O F Ne
H He

15. © Boardworks Ltd 2007
15 of 44
Missing elements!
In this periodic table the symbols are replaced by atomic
numbers. Some of the numbers are missing – where?
87 88 89 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118
55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
37 38 39 40 41 42 43 44 45 46 47 38 49 50 51 52 53 54
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
11 12 13 14 15 16 17 18
3 4 5 6 7 8 9 10
1 2
Two more rows of elements fit here.
They are called the lanthanides
and actinides.

16. © Boardworks Ltd 2007
16 of 44
The elements in the periodic table

17. © Boardworks Ltd 2007
17 of 44
Columns of elements
What are columns of elements called?
groups
1 2 4
3 5 6 0
7

18. © Boardworks Ltd 2007
18 of 44
Rows of elements
periods
What are rows of elements called?
1
2
3
4
5
6
7

19. © Boardworks Ltd 2007
19 of 44
Complete the sentences – periodic table

20. 20 of 44 © Boardworks Ltd 2007

21. © Boardworks Ltd 2007
21 of 44
Patterns: metals and non-metals
on the right (except hydrogen)
Where are these different types of elements grouped
together in the periodic table?
 metals
 non-metals
between metals and non-metals
 semi-metals
on the left and centre
Can you name a semi-metal element?
Semi-metals have some properties similar to metals and
other properties similar to non-metals.

22. © Boardworks Ltd 2007
22 of 44
Patterns: physical state
Only two elements are liquids at room temperature.
What are they?
 liquids
Where are these elements of different states grouped
together in the periodic table?
in the middle and on the right
 solids
on the far right (except hydrogen)
 gases
on the left, in the centre and on the right
 bromine and mercury

23. © Boardworks Ltd 2007
23 of 44
Metals to non-metals, solids to gases

24. © Boardworks Ltd 2007
24 of 44
Patterns: reactivity of metals
Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po
Rb Sr Y Zr NbMo Tc Ru Rh Pd Ag Cd In Sn
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga
Na Mg Al
Li Be
What happens to the reactivity of metals down a group?
Which is the most reactive metal?
increase in reactivity
increase
in
reactivity
What happens to the reactivity of metals along a period?

25. © Boardworks Ltd 2007
25 of 44
Which metal is more reactive?

26. © Boardworks Ltd 2007
26 of 44
Patterns: reactivity of non-metals
increase in reactivity
Group 0 elements are the most unreactive of all elements.
For the remaining non-
metals and semi-metals,
reactivity increases up a
group and along a period
from left to right.
Which is the most reactive
non-metal/semi-metal?
At Rn
Sb Te I Xe
Ge As Se Br Kr
Si P S Cl Ar
B C N O F Ne
He
increase
in
reactivity
unreactive

27. © Boardworks Ltd 2007
27 of 44
Which non-metal is more reactive?

28. 28 of 44 © Boardworks Ltd 2007

29. © Boardworks Ltd 2007
29 of 44
Patterns, atomic number and electrons
What links atomic number and the properties of elements?
The periodic table shows that patterns in the properties of
elements are linked to atomic number.
atomic number = number of protons
atomic number = number of electrons
number of protons = number of electrons
Electrons!
As atomic number increases by one, the number of electrons
also increases by one.
This means that the elements in the periodic table are
also arranged in order of the number of electrons.

30. © Boardworks Ltd 2007
30 of 44
How are electrons arranged?
Electrons are arranged in shells around an atom’s nucleus.
(The shells can also be called energy levels).
This electron arrangement is written as 2,8,8.
1st shell holds
a maximum of
2 electrons
2nd shell holds
a maximum of
8 electrons
3rd shell holds
a maximum of
8 electrons
Each shell has a maximum number of electrons that it can
hold. Electrons will fill the shells nearest the nucleus first.

31. © Boardworks Ltd 2007
31 of 44
Electrons in period 1
Elements in period 1 only have electrons in the first shell.
Why are there only two elements in period 1?
The first shell can only hold a maximum of two electrons,
so period 1 only includes the elements hydrogen and helium.
What is special about the outer shell of helium?
1 2
H He
1 2 4
3 5 6 0
7
1

32. © Boardworks Ltd 2007
32 of 44
Electrons in period 2
Elements in period 2 all have a complete first shell.
The second shell is completed one electron at a time going
across the period from left to right.
What is special about the outer shell of neon?
2,1 2,2 2,3 2,4 2,5 2,6 2,7 2,8
Li Be B C N O F Ne
1 2 4
3 5 6 0
7
What happens to electrons in the second shell in period 2?
2

33. © Boardworks Ltd 2007
33 of 44
Electrons in period 3
2,8,1 2,8,2 2,8,3 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8
Elements in period 3 have complete first and second shells.
The third shell is completed one electron at a time going
across the period from left to right.
What happens to electrons in the third shell in period 3?
Na Mg Al Si P S Cl Ar
1 2 4
3 5 6 0
7
What is special about the outer shell of argon?
3

34. © Boardworks Ltd 2007
34 of 44
What are the patterns of electron arrangement?
Consider the electron arrangements of the first 20 elements
in the periodic table.
What is the pattern of outer shell electrons in a group?
2,8,1 2,8,2 2,8,3 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8
1 2 4
3 5 6 0
7
1
2
3
4
2,1 2,2 2,3 2,4 2,5 2,6 2,7 2,8
1 2
2,8,8,1 2,8,8,2
What is the pattern of outer shell electrons across a period?
What is the pattern of full electron shells in a group?

35. © Boardworks Ltd 2007
35 of 44
Electron trends in the periodic table
Trends down a group:
The point at which a new period starts is the point at
which electrons begin to fill a new shell.
The number of a group is the same as the number of
electrons in the outer shell of elements in that group,
except for group 0.
 the number of outer shell electrons is the same;
 the number of complete electron shells increases by one.
 the number of outer shell electrons increases by one;
Trends across a period:
 the number of complete electron shells stays the same.

36. © Boardworks Ltd 2007
36 of 44
Electrons and groups

37. © Boardworks Ltd 2007
37 of 44
Groups and periods

38. © Boardworks Ltd 2007
38 of 44
What’s the electron arrangement?

39. © Boardworks Ltd 2007
39 of 44
Names of groups in the periodic table

40. © Boardworks Ltd 2007
40 of 44
Periodic table and electron structure

41. 41 of 44 © Boardworks Ltd 2007

42. © Boardworks Ltd 2007
42 of 44
Glossary
 atomic number – The number of protons in an atom.
Sometimes called the proton number.
 electron arrangement – A shorthand way of writing the
number of electrons in an atom’s electron shells.
 element – A substance made up of only one type of atom.
 group – A column in the periodic table containing elements
with the same number of outer shell electrons and similar
chemical properties.
 period – A row in the periodic table containing elements
with the same number of full electron shells.
 periodic table – The table that lists all the elements in
order of increasing atomic number, arranged into groups and
periods.
 property – Any characteristic of an element.

43. © Boardworks Ltd 2007
43 of 44
Anagrams

44. © Boardworks Ltd 2007
44 of 44
Multiple-choice quiz