What is a chemical equation?

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Lesson 30 What is a chemical equation?
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When you tear a piece of paper into tiny pieces,
you still have paper, right?
No chemical changes have been made to the paper,
only physical changes.
No new properties were made. The paper has the
same chemical makeup.
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A change like tearing paper is called a physical
change.
Physical change is when there is a change in the
appearance only. The chemical makeup of the
matter is exactly the same.
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What happens if you burn paper?
You no longer have paper.
Paper is a compound made up mostly of carbon and
hydrogen.
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When paper burns, it links up with oxygen from
the air. Three products form ash, water, and
carbon dioxide.
When paper burns, there is a change in the way
atoms link together. New products form, and
properties change.
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A change like burning paper is called a chemical
change.
In a chemical change, the chemical makeup of a
substance changes.
New products are formed, properties change.
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A chemical change is caused by a chemical
reaction.
The story of a chemical reaction is told by a
chemical equation.
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A chemical equation shows two things.
-which substances we start with (reactants)
-which substances we end up with (products)
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This is an example of a chemical equation
Fe S FeS
This equation describes the chemical reaction
that takes place when a mixture of iron (Fe) and
sulfur (S) is heated.
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Fe S FeS
The Fe and S are the reactants.
The FeS (iron sulfide) is the product.
The arrow means produces or yields.
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The properties of iron sulfide are different from
those of iron or sulfur.
In any chemical equation
-the reactants are on the left side of the arrow.
-the products are on the right side of the arrow.