Transcript Slide 1

Glossary
atom – The smallest particle that can exist on its own.
compound – Substance made up of two or more
different elements that are chemically joined together.
element – Substance made up of only one type of atom.
formula – The symbols and numbers that represent the
atoms in a substance.
molecule – Two or more atoms that are chemically joined
together.
periodic table – Table in which all known elements are
arranged based on their properties.
symbol – One or two letters that represent an element.
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© Boardworks Ltd 2005
2004
Tuesday, July 21, 2015
Title: How can we represent the changes when
new materials are made?
Keywords
Learning Objectives:
• word equation
We are learning….
• How do elements combine to make compounds with different
properties?
•How do we write word equations to show these compounds
being formed?
Starter:
Can you complete these symbol
equations and name the
compounds produced?
Combining elements
How is possible to have so many different materials from
a limited number of elements?
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© Boardworks Ltd 2005
2004
Combining elements
How do you get so many
different cheeses?
What is the key ingredient
in all cheeses?
Milk is combined with a
small number of ingredients
under different conditions to
make a huge number of
different cheeses.
In a similar way, a small number of elements can be
combined in many different ways to make a huge
number of different compounds.
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© Boardworks Ltd 2005
2004
What is a compound?
A compound is the substance produced when two or more
elements combine in a chemical reaction.
Two elements, hydrogen (H)
and oxygen (O), combine to
make the compound, water.
Which two elements combine
to make the compound
carbon dioxide?
A compound is always made up of two or more
different types of atom.
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Making a compound – carbon dioxide
A compound has very different properties to the elements
from which it is made.
elements
carbon
oxygen
combines
with
A black solid
which can be
used as a fuel.
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compound
carbon dioxide
to make
A colourless gas
which is essential
for life.
A colourless gas
which is used
to put out fires.
© Boardworks Ltd 2005
2004
Making a compound – water
What are the elements which make up water?
In what ways are the elements different to their compound?
elements
oxygen
hydrogen
combines
with
A colourless gas
which is used in
hot air balloons.
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compound
water
to make
A colourless gas
which is essential
for life.
A liquid which is
essential to our
lives and has many
different uses.
© Boardworks Ltd 2005
2004
Element or compound?
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© Boardworks Ltd 2005
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Word equations
When chemicals react with each other, different chemicals are
made. One of the best ways to describe what is happening is
by writing a chemical equation.
A chemical equation tells you which chemicals reacted together
(the reactants) and the new chemicals that were made in the
reaction (the products).
The simplest equation is a word equation. For example:
sodium + chlorine
Reactants always go on the
left!
→
sodium chloride
Products always go on the
right!
Burning magnesium
Some metals are very reactive. They easily take part in
chemical reactions to make new substances.
Magnesium is like this. If it is heated in a Bunsen burner,
it ignites and burns with a brilliant white flame.
The word equation for this reaction is:
Magnesium + Oxygen
Magnesium oxide
The symbol equation is:
2Mg
+
O
2MgO
Complete the worksheet