What is Chemistry?

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PHYSICAL OR
CHEMICAL?
CHANGES AND
PROPERTIES
WHAT IS CHEMISTRY?
 The
study of the
composition of
matter and the
changes that
matter undergoes.
WHAT IS MATTER?

Anything that has mass and volume (space it
occupies)
 All objects are made of matter
 It can be something that you can’t see.
 Examples:
Air
 Water
 You!

STATES OF MATTER
There
are three
states of matter
1. Solid
2. Liquid
3. Gas
SOLID
 Has
a definite shape
and volume
Shape of solid does
not depend on shape
of container
Arrangement of
particles: tightly
packed together

LIQUID
 Has
an indefinite
shape, flows, yet
has a fixed volume.
Particles are close
together but able
to flow
Takes the shape
of container

GAS
 Takes
both the
shape and volume of
its container
Gas can expand to
fill any volume
(unlike a liquid)
Particles within a
gas are far apart

States of Matter
SOLID
((
((
((
((
((
))((
))((
))((
))((
))((
))((
))((
))((
))((
))((
vibrating
LIQUID
GAS
))
))
))
))
))
moving;
close together
moving quickly;
far apart
Think-Pair-Share: Complete the state of
matter summary chart in your notes.
Phase
(State) of
matter
Solid
Liquid
Gas
Shape
(s)
(l)
(g)
Volume
Spacing of Movement
Particles of Particles
PHASES OF MATTER
Phase (State)
of matter
Solid
Liquid
Gas
(s)
(l)
(g)
Shape
Volume
Definite
Definite
Indefinite
Indefinite
Definite
Indefinite
Spacing of
Particles
Fixed
position;
very close
Close but in a
random
arrangement
Spread far
apart from
each other
Movement
of Particles
Vibrating
Moving:
close
together
Moving
quickly;
far apart
PHYSICAL VS. CHEMICAL PROPERTIES
Physical Property

A characteristic that can
be observed or measured
for a substance without
a change in the identity
of the substance
(chemical composition
does not change).

Ex: color, state of matter,
boiling point, melting
point, density, solubility
Chemical Property

A characteristic that
can be observed for a
substance only during a
change in the identity of
the substance; ability of
a substance to undergo
a chemical change

Ex: ability to rust,
ability to burn,
flammability, reactivity
Melting point
 Boiling point
 Color
 State of matter
 Odor
 Taste
 Texture

Density
 Electrical conductivity
 Solubility
 Adsorption to a surface
 Hardness
 Size
 Mass/volume
 Shape

Flammability
 Explosiveness
 Reactivity with acid
 Corrosiveness

Ability to Burn
 Ability to Rot
 Ability to Rust
 Ability to Decompose

**These properties are observed as
the chemical make-up of the
substance is changing**
DEMO: PHYSICAL OR
CHEMICAL CHANGE?
DEMO
#1:
 RECORD
OBSERVATIONS
 IS IT CHEMICAL OR
PHYSICAL CHANGE? Why?
DEMO
#2:
 RECORD
OBSERVATIONS
 IS IT CHEMICAL OR
PHYSICAL CHANGE? Why?
PHYSICAL VS. CHEMICAL CHANGES
Physical Change

A change in which
Chemical Change
(reaction)

only the physical state or
condition of a substance
is involved.
 the particles (atoms or
molecules) of a substance
retain their identity.
 Chemical composition
does not change
 No new products are
formed



Ex: dissolving, grinding,
melting
A change in which



A new substance
results (with new
physical and
chemical properties).
the particles (atoms
or molecules) of a
substance become
particles of a
different substance
Chemical
composition does
change
Ex: burning wood, rusting
PHYSICAL CHANGES
 All

changes of state:
Melting


Freezing


Gas becoming a liquid
Deposition/Solidification


Liquid becoming a gas
Condensation


Liquid becoming a solid
Boiling/Evaporation


Solid becoming a liquid
Gas becoming a solid
Sublimation

Solid becoming a gas
CHANGES OF STATE CONCEPT MAP
Deposition
•Freezing Milk
•Dissolving sugar
•Breaking a Vase
•Coloring water red
•Boiling Water
•Ice melting
•Melting Wax
•Breaking a glass
•Mixing sand and gravel
•Cutting of Hair
•Cooking
•Heating Sugar
•Leaves changing colors
•Rusting
•Burning
1.
Gas Produced
2. Precipitate Formed
3. Color Change
4. Temperature Change
5. Bright Light Formed
PHYSICAL VS CHEMICAL
CHANGES VIDEO
PARTNER PRACTICE
Identify
& Explain why
 Chemical
change
 Physical change
PART 1: MOLECULAR MODELS
A)
B)
C)
D)
E)
F)
PART 2: STATEMENTS
1.
2.
3.
4.
5.
Two elements react to produce a
compound
ice (H2O) melting
Cl2 + H2  2 HCl
a solid compound dissolving in water
(H2O)
Hydrogen peroxide decomposing
HOW DO
WE KNOW THE DIFFERENCE BETWEEN PHYSICAL AND CHEMICAL
Is it an Action
Word????
(-ing word)
Chemical
Change
AND
PROPERTIES?????
Is it a
Description????
Property
Change
New Substance
Made
CHANGES
Just Looks
Different
Physical
Change
Ability to do
something or
-ity word
Chemical
Property
Just describes
how it
looks/acts
Physical
Property
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