1.
8thGrade
ScienceSubject forMiddleSchool
ChangetoMaterial

2.
SIMPLECHEMICALREACTION

3.
Tableofcontents
Simple
Chemical
Reactioan
Neutralisation
Investigating
acids and
alkalis
Detecting
chemical
reactions
01
03
02
04

4.
Chemicalandphysicalproperties
The physical properties of a substance are features such as:
• what colour it is
• if it is a solid, liquid or a gas
• what its boiling or melting temperature is
• if it is heavy or light.
For example :
 iron are that it is a grey, heavy solid with a melting
point of 1538 °C.
 hydrochloric acid is that it is a colourless liquid

5.
Chemicalandphysicalproperties
The chemical properties of a substance are features such as:
• how acidic or alkaline it is
• how it reacts with water, acids or metals
• how readily it reacts.
For Example :
1. Some of the chemical properties of iron are that it
combines with sulfur when heated to form iron
sulfide
2. Iron combines with oxygen to form iron oxide or rust.
One of the chemical properties of hydrochloric acid
is that it is has a pH of 2

6.
IntroductiontochemicalChange
Chemical changes are different from physical changes.
physical change, no new substances are formed.
For example, when liquid water freezes, the water has changed
state but it is still the same substance after the change.
chemical change, new substances are formed.
For example, when iron and sulfur are heated together, they form
a new substance (a compound called iron sulfide)

7.
Example Chemical Changes
When the charcoal is heated and burned, a chemical change occurs.
• The substances in charcoal react
with oxygen in the air to form other
substances.
A chemical change is also called a
chemical reaction.
• One or more substances change into one or more new
substances during a chemical reaction.

8.
Differencebetween PhysicalandChemical
Changes
● Physical
○ A change in the state
○ Solid to liquid
○ Liquid to gas
○ Gas to liquid
○ Atoms/molecules of the
substances do not change
● Chemical
○ Atoms/molecules broken
down or combined to
form new substances
○ Properties of new
substances are different
than properties of the
substances that make
them up

9.
Simple
Chemical
reactions
01

10.
ChemicalReactions
● A chemical reaction is the
process in which one or
more substances are
changed to one or more
different substances to
create new substances.

11.
Reactantsand products
● In chemical reactions, you start with reactants that are
combined to make products.
○ The reactants are the starting
substances.
○ The products are the new substances
which result from the chemical reaction.

12.
WORD
Typesofchemicalequations
FORMULA
Venus has a beautiful name
and is the second planet
from the Sun
Mercury is the closest planet
to the Sun and the smallest
one in the Solar System

13.
Describingchemicalreactions
REACTANTS PRODUCTS
The substances that
react together
new substances made
in the reaction

14.
WordEquations
● Statements that indicate the reactants and products in a chemical reaction.
Ex. Iron + Sulfur  iron sulfide
● This is read as:
“Solid iron and Sulfur react (combine) to produce solid iron Sulfide”
The reactants (the substances that react together) are the iron and
the sulfur.
The products are the new substances made in the reaction. In this
reaction, there is only one product – iron sulfide

15.
somechemicalreactions,asubstancebreaksaparttomakenew
substances.Forexample,watercanbesplitaparttoformoxygen
andhydrogen
water → oxygen+hydrogen
Chemical reactions happen everywhere. They happen inside plants
when they grow and when they decay. Chemical reactions happen
inside your body to keep you alive, for example, when you digest food

16.
CHEMISTRY & YOU
Are the changes that happen to a burning
match chemical or physical changes?
How do you know?
A burning match is undergoing a
chemical change. There is a transfer
of heat, a production of light, and a
change of color. The composition of
the materials also changes during the
burning process.

17.
Burning
Burning is a chemical reaction.
When a substance burns, the
substance reacts with the
oxygen in the air. Sometimes
ashes are formed. The ashes
contain new substances.
The new substances in the
ashes are oxides.

18.
Charcoalismadeupoftheelementcarbon.Whencarbonburnsit
combineswithoxygenintheairtomakethegascarbondioxide.
Carbon→ oxygen + Carbondioxide
When magnesium metal is burnt, a white powder is formed. This powder is
magnesium oxide. A new substance has been formed from magnesium and
oxygen. Magnesium and oxygen are the reactants. Magnesium oxide is the
product. A chemical property of magnesium is that it burns in air to form
magnesium oxide by combining with oxygen

19.
Propertiesofreactantsand products
Example when burn magnesium. You can see that the properties of the
product are different from those of the reactants

20.
Reactionwithwater
Some substances react very violently with
water. Some substances do not react with
water at all.
Potassium (a metal) is very soft and can
be cut with a knife. This is a physical
property. Potassium is so reactive that it
has to be stored under oil to prevent it
reacting with the water vapour in the air.
This is a chemical property.
When a very small piece of potassium is
placed in a large trough of water,
hydrogen gas is given off. The reaction
produces so much heat that the gas burns

21.
ReactionwithAcid
When magnesium is placed in hydrochloric acid, bubbles of gas are
given off. The magnesium has reacted with the hydrochloric acid
and formed new substances. The gas is hydrogen, and magnesium
chloride has been formed. This is a chemical property of magnesium
When you see bubbles forming in a reaction, you know that a gas is being
produced. But you cannot tell what type of gas it is.
The diagrams show you how to test a gas to find out if it is hydrogen.
Hydrogen gas burns with a squeaky pop. To carry out the test you light a
splint and place it in the mouth of the test tube. When the hydrogen pops, it
is reacting with oxygen, in the air, to form water.