Download Notes: Phases of Matter

Phases of Matter
Solids, Liquids,
and Gases
I- DEFINING MATTER: Albert
Einstein said matter can be changed
into energy and energy into matter.
They are different forms of each
other.
A-Matter is anything that has mass and
takes up space.
B- All matter is made up of groups of
atoms called molecules.
C-Three states or phases of matter: Solid,
liquid, and gas.
Phase
Volume
Shape
Movement of
Molecules
Solid
Definite
Definite
Held Tightly
Liquid
Definite
Takes shape
of Container
Slide past
each other
Gas
Takes volume of
Container
Takes shape Move all over
of Container
II- How Particles are Arranged in Solids
particle in a solid vibrates around a fixed
point.
A-When a solid's particles are arranged in a
definite repeating pattern it is a CRYSTAL.
l-Crystals form when a melted
substance cools.
a- the size of the crystal
depends on how fast or slow it
cools.
~ slow large crystals.
~ fast smaller crystals.
B-When the particles of a solid are NOT
arranged in a pattern the solid is a
AMORPHOUS.
l-When the liquids cools too
quickly a amorphous solid forms
2-Amorphous solid are made up of long
chains of particles.
3-Unlike crystals which melt suddenly at
a given temperature, amorphous solids
melt gradually over temperature ranges.
III-How Particle of a Liquid Behave:
A- Surface Tension makes the surface of a
liquid act like an elastic sheet.
l-Cohesion force that keeps particles of the
same substance together. Causes surface
tension.
2-Adhesion force that attracts particles of one
substance to particles of another substance.
Forms the Meniscus.
B-Viscosity is the resistance of a liquid to
flow.
l-Heat makes liquids less Viscous,
2-Cooler temperature makes liquids
more Viscous.
C- Pressure is the amount of force acting
over an area.
l-Pressure acts in all directions.
2-Pressure of a liquid depends on
depth and density of the liquid.
PRESSURE
D-Buoyant force is the upward force
liquids exerts on objects.
l-Archimedes' Principle: states
that the buoyant force on an object
is equal to the weight of the
liquid/gas it displaces.
IV-How Gases Produce Pressure
A-Pressure is a force acting over an
area.
1. The pushing of gas molecules in a
tire make the tire go up.
2. Gravity acts like a container, keeping air
from escaping.
3. The gas molecules in our atmosphere
exert pressure on everything.
4. Air pressure is measured at sea level.
B-Changes in Volume and Temperature of
Gases
1. At a constant temperature, the pressure of a
gas increases when the volume of it's container
decreases.
a- If you reduce the container by
half the pressure doubles.
b- If you increase the containers
volume by half you decrease the
pressure by half.
2. If you increase the temperature of a
gas you increase the pressure, as
long as the container remains the
same size.
a-the gas particle gain energy and
bump into each other increasing the
force .
Gas Molecules
Heat
Source
Piston
Gas Molecules
C- Bernoulli’s Principle: as the
velocity of a gas/liquid increases,
the pressure it exerts decreases.
1- Plasma: is a special type of gas that
is broken up into positively and negatively
charged particles. Example neon in neon
signs.
D-Pascal's Principle states
that if the pressure of a
liquid/gas in one part of a
container changes the
pressure changes
throughout the container.
V- Changes in Phases of Matter
A- How matter changes from
one phase to another
1- Temperatures affect the
way particles are held
together. From solid to
liquid to gas.
0
0
a.Melting is a change of phase from solid
to liquid.
 The temperate at which solid melt is
its melting point.
 Melting point of water is 00 C. Iron
melts at 15250 C.
b.Freezing is the change of phase
from liquid to solid.
Freezing point is the
temperature at which a liquid
changes to a solid.
The freezing point of a
substance is the same as its
melting point.
c.Boiling point the temperature at which
a liquid boils.
 At its boiling point, a liquid changes
into a gas is called Vaporization.
d.Evaporation when a liquid changes from
a liquid to a gas with out reaching its
boiling point.
f.Sublimation process where ice changes
directly to a gas with out changing to a
liquid first. Example comet
B- Temperature Does Not Change
During Phase Changes
1.Latent heat or hidden heat is the
energy needed to change a substance
from one physical state to another.
 The temperature does not change as
long as the melting or freezing
continues.