1. properties be observed? What observations might
2.3 Chemical Properties
Key Questions
When can chemical
properties be observed?
What observations might
indicate that a chemical
change has occurred?
What is the difference
between chemical and
physical changes?

2. Observing Chemical Properties
A chemical property is any ability to produce a change in the ________________ of matter.
composition
Flammability is a material’s ability to _____________ in the presence of _______________.
Candle wax O2  CO2 + H2O
What happens to the size of your candle
over time?
burn
oxygen
Oxygen
gas
carbon
dioxide
Water
vapor
It gets smaller  converting to CO2 and H2O

3. Observing Chemical Properties
Reactivity
The property that describes how readily a substance ______________ _________________ with other substances is reactivity.
Example: Iron readily
reacts with oxygen to
form ____________
combines
chemically
rust

4. Observing Chemical Properties
Would you want to use iron to make jewelry?
Jewelry should be made of
substances that have ________
reactivity
No…too reactive!
low

5. Recognizing Chemical Changes
2.3 Chemical Properties
Recognizing Chemical Changes
Three common clues for a chemical change are a change in ______________, the production of a ______, and the formation of a __________________.
color
gas
precipitate
Color change – ripening banana
What are other properties of a
banana that will change as it
ripens?
Taste, texture

6. Recognizing Chemical Changes Production of a Gas
2.3 Chemical Properties
Recognizing Chemical Changes
Production of a Gas
When you mix vinegar with baking soda, _____________ of carbon dioxide form immediately.
A similar chemical change happens when you use baking powder as an ingredient in a cake
recipe. Bubble of carbon dioxide
____________ and cause the cake
to _____________.
bubbles
expand
rise

7. Recognizing Chemical Changes
2.3 Chemical Properties
Recognizing Chemical Changes
Formation of a Precipitate
Any _______________ that forms and separates from a ___________ mixture is called a precipitate.
When an acid is added to milk, proteins in the milk undergo a chemical change that causes them
to __________ together in clumps
and form a precipitate called
_____________________________.
solid
liquid
stick
cottage cheese

8. Is a Change Chemical or Physical?
2.3 Chemical Properties
Is a Change Chemical or Physical?
Are different substances present after a change takes place?
If yes, then the change is _____________
If no, the change is ________________.
chemical
physical
Heating iron to make a horseshoe…
Chemical or physical change?
It is still iron after heating

9. Which of the following is NOT a physical property?
Assessment Questions
Which of the following is NOT a physical property?
density
boiling point
flammability
conductivity

10. Which of these materials is not malleable?
Assessment Questions
Which of these materials is not malleable?
copper
aluminum
glass
gold

11. Assessment Questions
3. The process of filtration uses the difference in boiling points of substances to separate a mixture. True False
- distillation

12. 4. You can be certain that a chemical change has occurred when
2.3 Chemical Properties
Assessment Questions
4. You can be certain that a chemical change has occurred when
there is a visible change.
the change is irreversible.
the temperature changes.
a new substance is formed.