Physical Science Ch.5 State of Matter V.Y. Maverick B.T
Slide 2
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 dont 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. 2
Slide 3
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
dont 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 forces are trying
to bring them close. 3
Slide 4
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 its 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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Slide 5
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 water will not freeze, so organisms still can
survive during cold weather. 5
Slide 6
Vocabulary time Amorphous- Solids that dont have a repeating
pattern of molecules or atoms. Polymer- Material in which
individual molecules are made long chains of repeating units 6
Slide 7
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. The reason they are useful is because they have high melting
points, can be easily formed, and when they solidify at a cool
temperature, they still have good strength. 7
Slide 8
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 dont 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 silicon that we
just learn from the periodic table. 8
Slide 9
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 ??? 9
Slide 10
The Atmosphere of the Earth Air doesnt 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. 10
Slide 11
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. 11
Slide 12
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 conduc- tion 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. 12
Slide 13
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. Conductions
cannot take place in a vacuum space because there is no matter.
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Slide 14
Mechanical Properties Four main properties Strength - an object
that can obtain, but when its 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. 14