OBJECTIVE: WARM-UP: Give the basic definition/idea for a physical change & a chemical change.
Download ReportTranscript OBJECTIVE: WARM-UP: Give the basic definition/idea for a physical change & a chemical change.
OBJECTIVE: WARM-UP:
Give the basic definition/idea for a physical change & a chemical change.
Physical Change
•
Physical changes –
Just a change in appearance, no new substance made.
Physical property changes could include a change in: texture, shape, size, color, odor, volume, mass, weight, and density.
Chemical Change
•
Chemical changes
- A new substance is made & one or more indicators is present.
5 Indicators: Temperature change, Color change, Gas produced, Light Produced, Precipitate
What is this?
5
6
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84 º C = 183 º F
Was this reaction exothermic OR endothermic?
WHY?
8
At outdoor school you will notice the orange mud in the wetlands. This is caused by iron in the soil that rusts when exposed to oxygen in the water and the air.
( During what season of the year would a car rust the most? ( What made the iron rust faster?
• 5. Evaluation Activity: •
Look at the following slides and work with your partner to answer the questions on notebook paper
– (Found in Chem Interactions 2005 p 52)
- Observing Chemical Change
Energy in Chemical Changes
•A student places two substances in a flask and measures the temperature once per minute while the substances react. The student plots the time and temperature data and creates the graph at left.
- Observing Chemical Change
Energy in Chemical Changes
•
Reading Graphs:
– What was the temperature in the flask at 4 minutes?
– When was the first time the temperature was at 6ºC?
- Observing Chemical Change
Energy in Chemical Changes
•
Calculating:
– How many degrees did the temperature drop between 2 minutes and 5 minutes?
- Observing Chemical Change
Energy in Chemical Changes
•
Interpreting Data:
– Is the reaction endothermic or exothermic? Explain.
- Observing Chemical Change
Energy in Chemical Changes
•
Inferring:
– At what temperature did the reaction stop? How can you tell?
- Observing Chemical Change
Energy in Chemical Changes
•
Drawing Conclusions:
–Suppose the temperature in the flask increased instead of decreased as the reaction occurred. In terms of energy, what kind of reaction would it be? Explain.
Is it a chemical or physical change?
• Sugar dissolving in tea
OOPS!
Did it change size, color, shape (Physical Change)?
or Did it become different matter (Chemical Change)?
Correct!
Is it a chemical or physical change?
• Logs burning
OOPS!
Did it change size, color, shape (Physical Change)?
or Did it become different matter (Chemical Change)?
Correct!
Is it a chemical or physical change?
• Cutting paper
OOPS!
Did it change size, color, shape (Physical Change)?
or Did it become different matter (Chemical Change)?
Correct!
Is it a chemical or physical change?
• Crushing an aspirin
OOPS!
Did it change size, color, shape (Physical Change)?
or Did it become different matter (Chemical Change)?
Correct!
Is it a chemical or physical change?
• Metal rusting
OOPS!
Did it change size, color, shape (Physical Change)?
or Did it become different matter (Chemical Change)?
Correct!
Is it a chemical or physical change?
• Lighter fluid burining
OOPS!
Did it change size, color, shape (Physical Change)?
or Did it become different matter (Chemical Change)?
Correct!
Is it a chemical or physical change?
• An egg rotting
OOPS!
Did it change size, color, shape (Physical Change)?
or Did it become different matter (Chemical Change)?
Correct!
Is it a chemical or physical change?
• An egg breaking
OOPS!
Did it change size, color, shape (Physical Change)?
or Did it become different matter (Chemical Change)?
Correct!
Review Worksheets
• Work BY YOURSELF to complete the “Overview Chemical Reactions” WS, BOTH sides • Work BY YOURSELF to complete the “How Much Can You Remember…” WS, BOTH sides.
Go on to next slide when BOTH worksheets are done, BOTH SIDES of each.
Web Activities...
Physical Changes /Chemical Changes •Click here!
•Click here!
After webpage loads
, click 2 times on star
side of page.
on left
Try these sites to see if you and your partner really know about physical and chemical changes.
1.
http://www.edinformatics.com/math_science/a_p_chem.htm
2. http://www.quia.com/jq/48846.html
3. http://www.chem4kids.com/extras/quiz_reactintro/index.html
Look at some chemical reactions…
Click here
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