Unit A: 1.4 Matter exists in different physical states

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Unit A 1.4Matter exists in different physical
states

• Describe the different states of matter
• How the different states of matter behave
• Experiment with the behavior of different liquids

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States of Matter

• Ice (solid) water (liquid) Water vapor (gas)
• All are 2 hydrogen atoms and 1 oxygen atoms
• A state change does NOT change the molecules in a
  substance. The arrangement of the molecules DOES
  change

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• Which two characteristics determine the state of
  matter?
• Arrangement and motion of particles
• Which state of matter has particles that are
  farthest apart?
• Gas
• Which state of matter has particles that are
  generally closest together?
• Solid
• Which state of matter has particles that can
  slide past each other but cannot move freely in
  any direction?
• liquid

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Solids have a definite volume and shape

• Molecules are in fixed positions and are close
  together
• Molecules can vibrate but not move around
• Many solids have regular shapes (ice, table
  salt), though some do not (plastic or glass)

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Liquids have definite volume but NOT definite
shape

• Can measure the volume, of say water, milk, or
  oil, but the shape depends on the container it is
  in.
• Molecules are not tightly attached to one
  another, so can move independently can flow

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Gases have NO definite volume or shape

• Gas is compressible the molecules are very far
  apart compared with the molecules in a solid or
  liquid.
• Can pump more air into a container still a gas,
  same volume, different density (and less space
  between the molecules)

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Gas Behavior

• Exert a pressure against a container add more
  air to a bicycle tire feels harder
• The speed that gas molecules move increases with
  temperature.
• As they move around faster, the pressure on the
  inside of the container will increase.
• PPressure, TTemperature, VVolume (PVT)
• If the T of a gas stays the same, increasing P
  decreases V
• If the V of gas stays the same, increasing T also
  increases P
• If the P of gas stays the same, increasing T also
  increases V

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• Your Own Balloon
• Blow up two similar balloons.
• Let them sit for several minutes until their
  temperatures match the room temperature.
• Measure the room temperature with a thermometer.
• Measure the circumference of each balloon at the
  widest spot with a piece of string or a measuring
  tape. Record these measurements.
• Place one balloon in a refrigerator or freezer,
  and keep the other balloon at room temperature as
  a control.
• Measure the temperature inside the refrigerator
  or freezer with the same thermometer.
• Leave the balloon in the refrigerator or freezer
  for about an hour.
• Remove the balloon and measure the circumference
  around the widest spot as quickly as possible.
• Compare this measurement to the measurement made
  before the balloon was placed in the
  refrigerator!
• Allow the balloon to warm back up to room
  temperature and measure again! Also measure the
  control balloon.
• Now compare the numbers. What is the relationship
  between temperature and volume? Does the pressure
  stay the same inside of the balloon? Why or why
  not? Use the control balloon to make sure the
  refrigerated balloon did not leak. How would you
  do this?

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Contents within the balloon remain the same
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• How would you describe the volume and shape of
  the different states of matter?
• A solid has a definite volume and a definite
  shape. A liquid has a definite volume but no
  definite shape. A gas has no definite volume or
  shape
• How do particles in a solid, liquid, and gas
  move?
• Particles in a solid vibrate in place, particles
  in a liquid slide over one another, and particles
  in a gas move about easily in any direction.