Page 265 - Science Course 3 (Book 1)

Mo7-L4a: What is a Chemical Property?

Chemical Changes
The logs in this campfire
A chemical change is a change in matter in which are slowly burning down
the substances that make up the matter change into to ashes. The ashes are
composed of different
other substances with new physical and chemical substances than the logs.
properties.
They have a different color
and texture than wood.
The substances that undergo a chemical change no
longer have the same properties because they no
longer have the same identity. Key Concept

What is a Chemical Property?
What are signs of a chemical changes?

Signs of Chemical Change

Signs of chemical changes include the formation of
bubbles or a change in odor, color, or energy.

These signs do not always mean a chemical change
occurred.

The only proof of chemical change is the formation
of a new substance.

Leaves turn color in the
fall because of chemical
changes in the leaves

When you fry an egg,
the heat changes it into
different substances with SUMMARY
different properties. For
example, the clear liquid What is a Chemical Property?
part turns into a white
solid A chemical property is observed only as a
material undergoes chemical change and
Some of these copper changes identity.
pennies are bright and
shiny. Others are dark Signs of possible chemical change include
and dull. The dull pennies bubbles, energy change, and change in odor
have tarnished. Their or color.
copper has combined
with oxygen in the air to
form a new substance
with different properties.

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