Observing Chemical Change
• Matter is anything that has mass and
takes up space.
• Chemistry is the study of matter and how
matter changes.
• Changes in matter can be described in
terms of physical changes and chemical
changes.
Properties of Matter
• PHYSICAL PROPERTIES: Properties of the
substance that can be observed without
changing the substance to another substance.
Example: Color, shape, size, melting point,
ability to conduct heat and electrical
current…………
• CHEMICAL PROPERTIES: Properties of a
substance that describes its ability to change
into other substances. Example: Does it react?
Or it does not react? Is it flammable? Or it is not
flammable?
Changes of Matter
• Physical Change: Changes that change the
form or the appearance of the substance but
does not make the substance into another
substance.
• Chemical change: Is a change in matter that
produces one or more new substances,
Chemical change is also known as
Chemical Reaction. In Chemical reactions two
or more substances known as reactants
undergo change and form new substances
known as products
• Chemical Change occurs when bonds break
and new bonds form
Evidence for Chemical Change
• Chemical reactions involve changes in
properties and changes in energy that you
can observe.
• Evidence, (Clues) for chemical
reaction:
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Solid formation (precipitate)
Gas formation
Color change
Energy change
Changes in energy
• Endothermic Reaction: Chemical
reactions where energy is taken in.
• Exothermic Reaction: Chemical reactions
where energy is given off.