Science Starter
Two identical sugar candies are unwrapped and
placed in beakers of water. 15 minutes later
an experimenter returns to the room to find
that one piece of candy has disappeared and
the other is nearly the same volume as at
start. Which of the following was most likely
different about the two beakers?
a. Temperature of the water
b. Purity of the water
c. Water was swirled more
d. Amount of water
Physical and
Chemical Changes
Physical Change- occurs when some of the
properties of a material change, but the
substances in the material remain the same.
*water boiling, heating butter in a pan,
cutting, slicing,
Some physical changes can be reversed!!
**Think of WATER**
Chemical Changes-occurs when a substance
reacts and forms one or more NEW
substances.
*cakes baking, leaves changing colors, food
digesting your tummy, RUST
EVIDENCE OF A CHEMICAL CHANGE:
-Change in color- when something rusts, or
burns
-Production of a gas- vinegar and baking soda
bubble, cake rises in the oven
-Formation of a Precipitate-any solid that
forms and separates from the liquid
mixture. (milk curdling, cottage cheese)
PRACTICE!!!
Identify whether the following are physical
or chemical changes:
Smashing glass
Melting ice cubes
Digesting lunch
Freezing OJ
Burning brush
Cutting a diamond
Tarnishing silver
Bleaching hair
Science Starter (23)
Identify the following as a physical or chemical property of matter.
Soluble in Water
Melts
Magnetic
Ductile
Reacts with Air
Combustible
Insoluble in Water
Crystalline
Flammable
Conducts Electricity
Corrodes
Brittle
Evaporates
High Boiling Point
Rusts
Viscous
Yellow Color
Lustrous
States of Matter
A. The Kinetic Theory
1. All matter is composed of
small particles (atoms,
molecules, or ions).
2. They are in constant, random
motion.
3. They constantly collide
with each other and with the
walls of their container.
Solids…
• Particles are closely packed together
• Force that holds the particles together is
strong
• Particles vibrate, but do not slip past one
another
• Definite Shape, Volume
Liquids….
• Force that holds them together is
strong, but they can slip past one
another
• They can be poured
• They are fluids…because the particles
can move past one another
• Definite volume, but take the shape
of a container
Gases…
• Particles move fast enough to
overcome the force of attraction
• Not in contact with each other
• Move randomly and in straight lines
until they bump into each other and
bounce off one another
• Take the shape of container and fill it
evenly
The 4th State…
Plasma….
• Most common state of matter. Makes up
99% of known matter including the sun and
stars.
• Plasma does not have a definite shape or
volume. Particles are electrically charged or
ionized.
• Ex….Lightning and Fire (natural)
Fluorescent Light (artificial)
Phase Changes
B. Phase Properties
Particle Properties
Phase Proximity Energy
Motion
Volume
Very close
little
vibrational
definite
Solid
close
moderate rotational
definite
Liquid
far apart
a lot
translational indefinite
Gas
Shape
definite
indefinite
indefinite
Phase Changes
Type
From
To
Example
Freezing
Liquid
Solid
Water freezing
to form ice
Melting
Solid
Liquid
Ice melting to
form water
Boiling
Liquid
Gas
Water boiling to
form steam
Sublimation
Solid
Gas
Ice cubes
evaporating
Condensation
Gas
Liquid
Dew forming on
grass
Evaporation
Liquid
Gas
A puddle drying