Structure and Bonding

1. Year 9
Structure and Bonding
Version 3.1

2. Atomic structure
This is known as the
Bohr model.
The nucleus contains protons (p) and neutrons (n). Electrons (e) orbit the
nucleus, arranged in shells or energy levels.
P
P
N
N
N
P
N P
P
N
N
P
Electron
-ve
Nucleus
Neutron
Proton
+ve
Shell 1
Shell 2

7. Protons are positively charged; electrons are negatively charged; neutrons have o
electrical charge.
Atoms have no overall charge because the number of protons = number of
electrons.
Atom charges
All matter is made up
of atoms. Atoms
consist of protons,
neutrons and electrons.
The charges of
protons and electrons
are equal and opposite.
Gaze
SJ

8. Atom summary
Subatomic
particle
symbol Mass
compared
to a proton
charge location
Proton
Neutron
Electron
p
n
e
1
1
1/1840
+1
0
-1
In the
nucleus
In the
nucleus
Moving
outside the
nucleus

12. Atomic number = number of protons. Symbol = Z
Atomic Number
The atomic number is unique for each element.
An atom has the same number of electrons as protons.
The periodic table is arranged in order of an elements atomic number.

13. Mass number = number of protons and neutrons. Symbol = A
Mass Number (atomic Mass)
The Mass number is the number of protons + number of neutrons.
The Mass number is close to double of the Atomic number.
An isotope is an element with a different Mass number because it has more or less
neutrons than normal.
Mass number

14. Complete the Table
Element Symbol Atomic
number
Mass
Number
Number
Protons
Number
Electrons
Number
Neutrons
Lithium 7
O 10
5 6
Magnesium 12
7 7
Na 12
1
27 13
19 40

15. Activity

16. Cont

17. Cont

18. Cont

19. Matter
Mixtures Pure Substances
Elements Compounds
Metallic
Non-Metallic
Ionic
Molecular

20. s
t
P
r
e
v
i
o
u
s
N
e
x
t
History of Atomic Theory
1830
Gaze
SJ

21. If I were…
an element
I could be: copper, aluminium, iron,
oxygen or nitrogen, for example.
I would be a substance made up
of one type of atom only.
I would have individual properties,
different to other elements.
All elements are listed with their
symbols on the periodic table.
I would have a name and a symbol, e.g. Oxygen has
the symbol O and Iron has the symbol Fe.
My symbol is usually just
one or two letters.

22. Element Symbols
Elements consist of only one type of atom.
Each element can be represented by a chemical symbol.
>Most symbols are one or two
letters, formed from the name of
the element,
e.g. Hydrogen H, or Helium He.
>The first letter of the symbol is
always a capital letter. Any other
letters are lower case.
e.g. Helium is He not HE
>If the symbols are not based on a
elements English name then it is
most likely to be based on it’s Latin
name, the original language of
Science.

23. History of Atomic Theory
1830
Gaze
SJ

24. If I were…
a compound
I would contain two or more
elements joined together.
I am different to a molecule because the
atoms joined are of different elements.
I could be carbon
dioxide, CO2.
I would have been formed
from a chemical reaction.
With lots of energy, I could be split
back into my original elements.
I would have different properties from the
elements that joined to form me.
The ‘join’ between my atoms is
called a chemical bond.

25. If I were…
a mixture
I would contain two or more elements or
compounds not joined together.
I am often made by dissolving a solute into a
solvent to create a solution.
I could be seawater or
air, for example.
I would have the properties
from the parts I am made of.
I could be separated into my individual parts
with physical methods e.g. filtration.

27. Periodic Table
The Periodic table lists elements in order of their atomic
number.

28. Structure of Periodic Table
The columns (downwards) of a periodic table are called groups.
The rows (across) of a periodic table are called periods.
Elements in the same group all
have the same number of
electrons in their outer (or valence)
shells.
Elements in the same period
all have the same number of
shells of electrons in their
atoms

30. Elements can be classified as metals or non-metals. A few elements are called
semi-metals or metaloids (e.g. boron and silicon), because they show some, but
not all, of the properties of metals.
Metals and Non-Metals

39. Which Element Am I?
Photo courtesy of Chemical Heritage Foundation, via Wikimedia Commons

40. I contain 8 neutrons.
?

41. My relative atomic mass is 24.
?

42. I contain 3 protons and 4 neutrons (Li).
?

43. I have 5 electrons altogether.
?

44. I have 3 shells and in my outer shell I
have 2 electrons.
?

45. My symbol is Si.
?

46. I have the electron configuration 2, 8, 3.
?

47. I have 10 electrons my uses is in
lights.
?

48. I contain 11 electrons.
?

49. I am in group 5, period 2 (N).
?
Photo courtesy of Sarah_Ackerman, via WikimediaCommons

50. Photo courtesy of Chemical Heritage Foundation, via Wikimedia Commons

52. Chemical Equations
• Chemical equations are a simple way to describe how different chemicals are
made in a chemical reaction.
• The equation tells us which chemicals are reacted together. These are called
the reactants and are found on the left-hand side of the equation.
• Chemistry is like baking. Imagine we are making a cake. The following
ingredients would be our reactants:
• The equation tells us which chemicals are formed. These are called the
products and are found on the right-hand side of the equation.
• Our product is the thing that we have made. If chemistry is like baking then
our product would be a cake.

53. Chemical Equations
lithium + fluorine  lithium fluoride
• However, scientists often use symbol equations. Symbol equations give us
more detail as they not only show the type of atoms that are present in the
reaction but also how many.
• What would the word equation be for this reaction?
• For example, in a reaction vessel, lithium and fluorine are reacted
together to produce lithium fluoride.
• The simplest type of equation is a word equation. A word equation uses
words to describe the reaction.

54. Naming Compounds
In chemical equations, reactants react together to form products. The
products formed are compounds.
Example
magnesium (element) + oxygen (element)  magnesium oxide
(compound)
Naming chemical compounds depends upon a set of rules:
1. If a compound name ends in the suffix ‘–ide’, this usually indicates that
it contains only two elements.
Example
sodium + oxygen  sodium oxide
2. If a compound name ends in the suffixes ‘–ate’ or ‘–ite’, this usually
indicates that it contains three or more elements. Of the three elements,
oxygen is always one of them.
Example
iron + bromine + oxygen  iron bromate

55. Balancing Chemical Equations
• Look at the images below of children on a see-saw. Which one is
balanced?
• Balancing a symbol equation is similar to a see-saw.
• To balance a see-saw, the children’s mass on each side must be the
same.
• To balance a symbol equation, the number of atoms on each side must
be the same.

56. Balanced equations must have the same number of atoms on each side of the
equation i.e. reactants and products.
Balancing equations
2Na + 2H2O = 2NaOH + H2
Na Na Na Na
O O
O O
H H H H
H H
H H

57. Balancing Method
Step 1 – Write down the chemical equation.
Step 2 – Draw a straight line from the arrow down
the page.
Step 3 – List the elements that are on the left-hand
side of the equation next to the line that you have
just drawn.
Step 4 – List the elements that are on the right-
hand side of the equation.
Step 5 – Count how many of each element you
have.
Step 6 – Identify which elements have different
amounts on each side.
Step 7 – Through trial and improvement, place
numbers in front of the chemical formulae to
balance the equation.
Na + H2O  NaOH + H2
Na
H
O
1 1
2 3
1 1
Na
H
O

59. States of Matter Introduction
Solids, Liquids and Gases

60. • To define matter.
• To state the three states of matter.
• To compare and contrast the three states of matter.
• To understand that matter can exist in three states.
Learning Objective
Success Criteria

61. • Everything is made up of matter.
• So what is matter?
• How do we know it exists?
Starter: What Is Matter?

62. • Everything is made up of matter.
• Matter is any substance that has mass
and takes up space (volume).
• Your desk is made of matter.
• Your pencil is made of matter.
• You are made of matter!
Matter

63. There are five states of matter.
You will learn about three of these in KS3 Science.
Matter
The 3 states of matter you need to know are:
solid
liquid
gas

64. Write the following subheadings in your book with 3-
4 lines in between each of them:
Solids in the Classroom
Liquids in the Classroom
Gases in the Classroom
Identifying Types of Matter

65. Now in pairs you have two minutes to look around the
classroom and write down as many solids, liquids and
gases you can think of!
Identifying Types of Matter
One minute left!
Time’s up!

66. Identifying Types of Matter
Now in pairs you have two minutes to look around the
classroom and write down as many solids, liquids and
gases you can think of!
Circle one answer that you think no-one else in the class has written down.
Add at least three new answers as you listen to your classmates.

67. Properties of Types of Matter
What makes a solid different from a liquid, or a gas?
These features are called properties.
(In science this doesn’t mean a house!)
For example:
hard, soft, can flow, invisible.
You have already used some
properties to successfully
identify solids, liquids and
gases in the classroom.

68. Properties of Types of Matter
What makes a solid different
from a liquid, or a gas?

69. In small groups you are going to describe the properties of the
three states of matter: solids, liquids and gases.
Properties of Types of Matter
Challenge:
Can you write your description in
20 words or less?
Not sure where to start?
Imagine you were
describing your state of
matter to an alien from
outer space!
Points to include:
• What does it feel like?
• What does it look like?
• Can you squash it? Pour it?
• Plus anything else you can think of!

70. • Have a fixed shape.
• Cannot be squashed (compressed).
• Cannot flow.
• Particles cannot move, but can vibrate on the spot.
Properties Key Points: Solids

71. • No fixed shape - takes the shape of the container.
• Cannot be squashed (compressed).
• Can flow.
Properties Key Points: Liquids

72. • No fixed shape - takes the shape of the container.
• Can be squashed (compressed).
• Can flow.
Properties Key Points: Gases

73. I can define matter.
I can state the three types of matter.
I can compare and contrast the three types of matter.
What Did You Achieve Today?

77. Chemistry – States of Matter
Changing State

78. • To list the different changes of state.
• To identify which change of state is happening.
• To describe what happens as matter changes between states.
• To understand how matter can change from one state to another.
Learning Objective
Success Criteria

79. Starter
What connects these pictures?
Challenge: What is the opposite of your word?

80. States of Matter Recap
There are three states of matter:
solids liquids gases

81. Changing State
Matter can change from one state to another.
This means the particles will
be arranged differently and
so the properties of the
substance will change.

82. Time’s up!
One minute
remaining!
Identifying Changes Activity
In pairs you have two minutes to define the keywords
for each change of state from letters A to D!
A
B
C
D
Timer

83. Answers
melting
freezing
evaporating
condensing

84. New Keywords
sublimation
deposition

85. New Keywords
By Christopher from Salem, via Wikimedia Commons
Photo courtesy of james_mann, via Flickr.com
Dry ice happens because solid
carbon dioxide sublimates at
room temperature and turns
straight into a gas!
Snow happens because gaseous
water vapour deposits in clouds
and turns straight into a solid!
sublimation
deposition

86. How Does This Happen?
melting
evaporating
If particles in a solid are
heated up, they gain
kinetic energy and move
slightly apart.
If particles in a liquid are heated up,
they gain more kinetic energy and
move further apart.

87. How Does This Happen?
freezing
condensing
If particles in a liquid are
cooled, they have less
kinetic energy and move
even closer together.
If particles in a gas are
cooled, they have less
kinetic energy and move
closer together.

88. • The element with the highest
melting point is tungsten.
• It has the symbol ‘W’ from the
word ‘wolfram’ from the mineral it
was discovered in.
• Tungsten comes from Swedish for
‘heavy stone’.
Melting and Boiling Points
Pause for Thought
Tungsten is often used as the
filament inside of lightbulbs
- why do you think this is?

89. To overcome some of the forces between the particles
and make tungsten melt from a solid into a liquid, you
must heat it to 3422°C!
To overcome all of the forces between the particles
and make tungsten boil from a liquid into a gas, you
must heat it to 5555°C!
Melting and Boiling Points

90. The element with the lowest melting
point is helium.
It has the symbol ‘He’ from the Greek
God ‘Helios’ who was thought to drive
his chariot of the sun across the sky
every day.
Melting and Boiling Points
Helium exists as a gas at room
temperature and is often used in
balloons as it is less dense than air.

91. To turn helium from a gas into a liquid you
must cool it to below -268°C!
To turn helium into a solid you must cool it
even further to below -272°C!
Melting and Boiling Points

92. • Melting: a s changing into a l .
• Evaporating: a changing into a .
• Condensing: a changing into a .
• Freezing: a changing into a .
Definitions
Words to use: solid, liquid and gas.
Key Terms
Check your spelling as you
write each term down.

93. • Melting: a s changing into a l .
• Evaporating: a l changing into a g .
• Condensing: a g changing into a l .
• Freezing: a l changing into a s .
Definitions
Challenge: Can you remember
the two new keywords?
Key Terms
Check your spelling as you
write each term down.

94. • Melting: a solid changing into a liquid.
• Evaporating: a liquid changing into a gas.
• Condensing: a gas changing into a liquid.
• Freezing: a liquid changing into a solid.
Definitions
Challenge:
Sublimation: a solid changing directly into a gas.
Deposition: a gas changing directly into a solid.

95. Stearic acid is a white waxy solid at
room temperature.
You will be given stearic acid as a
hot liquid and will record when it
becomes a solid (solidifies).
Investigating Freezing Points Practical

96. Aim: Follow the worksheet to safely complete the practical.
Lab Safety Rules
Remember:
• Stand up at all times.
• Wear safety goggles at all times.
• Tie long hair up.
• Report any accidents to the teacher or the TA asap.
• Do not take your eyes off your equipment.
• Work well as a team and ask how to pack away.
• Most of all stay focused and enjoy!

97. Complete the five quick questions on your practical sheet.
Plenary

98. • I can list the different changes of state.
• I can identify which change of state is happening.
• I can describe what happens as matter changes between states.
What Did You Achieve Today?

99. Investigating Freezing Points Stearic Acid
Practical

100. Activity
• Changing the state