Transcript 14-11-(19NOV14) Notes-About Phys and Chem Changes

Bell
Work
SPI 0807.9.1
Atoms
Science
The three sub-atomic particles
in atoms are called…
Instructions
Protons,
and electrons
1) First neutrons,
click on "View"
from the top-menu bar.
2) Then click on "Slide Show" from the drop-down menu.
Answer
4 questions
on your
paper.
3) Thenthese
use the
right-arrow
button
on your keyboard to
1)advance
How many
protons
it have?
through
thisdoes
presentation.
2) How many neutrons does it have
3) How many electrons does it have?
4) What is lithium's atomic number?
3
Li
Lithium
6.9
Here is a model of
a lithium atom
Bell
Work
SPI 0807.9.1
Atoms
Science
1) How many protons does it have?
Three
2) How many neutrons does it have?
Four
3) How many electrons does it have?
Three
4) What is the atomic number?
Three
Legend
=protons
=neutrons
3
=electrons
Li
Lithium
6.9
Here is a model of
a lithium atom
Notes
SPI 0807.9.8
Physical & Chemical Changes

Two Types of Changes
Physical changes
Chemical changes
Physical Changes
Changes the appearance of an object, but does not
actually change the composition of the object
Physical changes do not form new substances
In other words, the way it looks is changed, but
what it is does not change
Can be fairly easily undone or reversed
Notes
SPI 0807.9.8
Physical & Chemical Changes

Physical Changes: changes the appearance of an object, but does
not actually change the composition of the object
Physical Changes Do Not Form New Substances!
Notes
SPI 0807.9.8
Physical & Chemical Changes

Physical Change:
It looks different, but is still the same material.
No chemical reaction has occurred.
Example: Changes of state/phase ARE NOT chem reactions
In other words, liquid to solid to gas is only a physical change
Liquid Water
Solid Water
Water Vapor
H2O
H2O
H2O
Notes
SPI 0807.9.8
Physical & Chemical Changes

Physical Changes: changes the appearance of an object, but does
not actually change the composition of the object
Examples of Physical Change
Melting
Freezing
Boiling
Cutting
Crushing
Tearing
Breaking
Smashing
Dissolving
Notes
SPI 0807.9.2
Chemical Change Outcomes

Chemical Change:
Is the result of a chemical reaction & a new substance is formed
Can not be easily undone or reversed
Chemical Change Indicators
There may be a change in odor
Heat may be given off
It may explode
 It may fizz or foam
Sound may be heard (sizzle, boom, or bang)
Light may be given off
It may change color
Also, it may form a solid substance called a precipitate
Link: Chemical and Physical Changes-Video
Notes
SPI 0807.9.8
Physical & Chemical Changes

TALK