Download Chapter 4, section 1 Chemical Changes

Chapter 4, section 1
Chemical Changes
I will describe the signs of a chemical
change in matter.
Agree
1._______
Disagree
All chemical changes result in a new
________ substance being formed.
All chemical reactions produce heat.
2._______
________
3._______
A chemical reaction caused the Statue of
________ Liberty to become green.
4._______
A change in smell is usually a sign of a
________ physical change
5._______
________
Some chemical reactions can create light.
I. Chemical Change
A. Occurs when bonds in compounds
break and new compounds form
1. In a physical change,
compounds remain the same
Metal elements bonding with oxygen
II. Evidence
A. chemical reactions will always
have:
- formation of a new substance
- a change in energy
http://www.youtube.com/watch?v=66kuhJkQCVM
B. Visual Evidence:
1. Precipitate – when two liquids
react and form a solid substance
2. Color change
3. Gas produced
4. Change in odor (smell)
http://www.youtube.com/watch?v=DITY2rXYU-I
Tons and Tons of Precipitation Reactions!
http://www.youtube.com/watch?v=JAeOP2MfrDY&list=TLJvZzUIA5KeR
y6b7rNi2dHxKjeqYsLjFE
C. Energy Evidence
1. Temperature decrease =
endothermic
2. Temperature increase =
exothermic
http://www.youtube.com/watch?v=Jzoi7dJAiSc&feature=related
Let’s Review Chemical Changes!
http://www.youtube.com/watch?v=cZMkqagL8Ps
Agree
1._______
Disagree
All chemical changes result in a new
________ substance being formed.
All chemical reactions produce heat.
2._______
________
3._______
A chemical reaction caused the Statue of
________ Liberty to become green.
4._______
A change in smell is usually a sign of a
________ physical change
5._______
________
Some chemical reactions can create light.
Please pull out your science
book to pg 660 and start
reading