Physical Science
Ch.5 State of Matter
V.Y. Maverick B.T
Atoms and Molecules
A fluid is a form of matter that flows when any force is
applied, no matter how small. The best example of fluids are
Liquids and Gases.
Molecules in liquid, phases of matter that can flow and
change shape but have constant volume, have space to move
around, but the molecules are tighter than gas. Molecules in a
solid object don’t move around at all and are really packed
together, so they are not allowed to change shape. Gases are
the most free to move because they are far apart, so they can
change the shape.
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Intermolecular forces
• In atoms there are two types of actions,
the stronger forces are between atoms
that bond together into molecules and
compounds, the weaker type are between
molecules but don’t bond together.
• Intermolecular forces are forces
between separate atoms and molecules
that are attractive at a distance, but
repulsive at close range. In addition,
thermal energy causes molecules to
spread apart, and the intermolecular
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Melting and Boiling
• Melting point is a temperature in which a
substance changes form a liquid to a
solid. Ice melts when it is at 0 degree and
it’s lacking heat.
• Added enough thermal energy, and
intermolecular forces are completely
overcome, the liquid will become gas.
• Water will boil when the temperature is
at 100 degrees.
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Melting Points of Common substance
Most materials have higher density as
a solid than as a liquid. Solid water
resembles a honeycomb. The water
will freeze because the honeycomb
structure spreads slightly within
itself, so this causes the volume to
increase, but the mass stays the same.
Ice will float on the water in winter
because it has less density than water.
However, the temperature
below the
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Vocabulary time
Amorphous- solids that don’t have a
repeating pattern of molecules or atoms.
Polymer- Material in which
individual molecules are made long
chains of repeating units
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In an easy way to represent a
polymer is plastic because plastic is
in the family of material in
polymer. A polymer is when
individual molecules gather
together to make a long chain of
repeating units. Also, polymers are
very useful in our lives, like the
plastic containers, sandwich bags,
etc. all need polymers
to be made.
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Crystalline solids
Crystalline is the solid that has a
repeating pattern of atoms, so it look
like crystal. Most of the naturally
occurring solids on Earth are
crystalline. The evidence of those things
is when you look under the microscope,
you can see the shape of crystal.
However, metals are also crystalline, but
they don’t have the shape like crystal
because tiny crystals is fused to be
together in a jumble of different
orientations. Most part of the
crystalline is made from
the element
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Pressure
• Pressure is created when a force is applied to a fluid.
• Pressure will occur in every direction because of the
collisions between atoms.
• Under the microscope, we will see trillions of atoms
bouncing off each other and the wall per second.
• All of this interaction causes pressure.
Why ???
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The Atmosphere of the
Earth
• Air doesn’t have an actual shape, but it does surrounding
us.
• Air is the most important gas for all living things.
• In the universe, atmosphere is a kind of air surrounding
the earth.
• Atmosphere is a mixture of nitrogen, oxygen, other
gasses, and water vapor..
• Rain is represents of the atmosphere that drops rapidly
because the warm air saturated with the water vapor.
• Cold air has more dense than warm air. Warm air needs
ground to expand and warm.
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• Convection is the transfer of heat
through the motion of fluids.
• When we cook dinner in the kitchen,
we will feel hot because the air
transmits the heat to us.
• Convection will occur when the
fluids expand because of heat.
• Natural convection occurs when the
fluid become heated it will increase
the volume but not the mass
• Hot water will have lower density
than the cold; this is the reason why
hot water will rise to the top.
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Heat Conduction in Solids
• Heat Conduction – when we hold something hot
in our hands, we can feel that heat transfer from
the object to
our hands. So Heat conduction is the transfer of heat
by direct contact of particles
of matter.
• Thermal Equilibrium – a condition where
temperature is the same and no heat flows.
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Thermal conductors and Insulators
• Conduction can occur in
liquid, gas and solid.
• Solid is the best conductor
because inside the solid
molecules are packed closer.
• Thermal conductors are
materials that transfer
easily; the opposite are
insulator conductors which
transfer heat poorly.
Examples of thermal
conductor materials are
silver, copper, gold, etc.
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Mechanical Properties
• Four main properties
– Strength - an object that can obtain, but
when it’s over the limit, the object will break.
– Elasticity - an object that is able to stretch
and bounce back.
– Brittleness - the opposite of elasticity, it
cant bend and if you drop it, it will break.
– Ductility - a solid material's ability to
deform under tensile stress.
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The End
Thank you
V.Y, & B.T
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