Chemicals &
Chemical Change
Chemistry?
• Chemistry is the
study of matter.
• Matter is anything
that has mass and
takes up space
(volume).
• All matter is made up
of tiny particles called
atoms. (Atoms must
have a mass and
take up space.)
Classifying Matter
Classifying Matter
• Pure Substance – A substance in which all
of the particles are the same.
– Element – Pure substance that is made of only
one type of atom and it can’t be broken down
into a simpler substance.
– Compound – Pure substance that contains two
or more different elements in a fixed
ratio/proportion.
• Mixture – A substance that is made of two
or more different types of particles.
– Homogeneous mixture (AKA Solution) – A
mixture that looks the same throughout – it has
only one phase.
– Heterogeneous mixture – A mixture that has a
non-uniform composition. The different parts are
easily identifiable and can usually be separated.
Properties of Matter
• Properties are characteristics that can be
used to describe something.
• A physical property is a characteristic of a
substance that can be described when the
substance is by itself.
– State, colour, hardness, odour, melting and
boiling point are some physical properties.
• A chemical property is a characteristic
behaviour that occurs when the substance
is exposed to another substance.
– Combustibility, reactivity with acids, corrosive
and the ability to oxidize are chemical properties.
Chemical vs. Physical Change
• A physical change occurs when a
substance undergoes a change in size
or state. The substance does not
change into another substance – it
stays the same!
H2O (l)  H2O (s)
• A chemical change occurs when a
substance undergoes a change and
becomes a new substance with new
properties.
2Na (s) + Cl2 (g)  2NaCl (s)
Chemical Tests
• In your notes…
– Indicate what a
chemical test is
used for in the lab.
– Outline the
chemical tests for
oxygen, hydrogen,
carbon dioxide
and water.
Lab Safety Symbols
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•
•
•
•
•
•
•
•
Poison
Flammable
Explosive
Corrosive
Toxic
Highly Reactive
Oxidizing Agent
Biohazard
Radioactive
That’s All I Got…