chp 3-1 solids liquids gases - leilehua high school...
Post on 20-Aug-2018
213 Views
Preview:
TRANSCRIPT
2/2/15
1
Solids, Liquids, &
Gases (Section 3.1)
Describing The States of Matter
• Materials can be classified as solids, liquids, or gases based on whether their shapes and volumes are definite or variable
Solid • Set shape and
volume • Particles
tightly packed • Incompressible
Liquid • Fluid • Constant volume • Shape of container • Particles can move • Incompressible
Gas • Shape of container • Fills the entire volume of
the container • Particles very far apart • Compressible
Other States of Matter
• On earth most matter exists as a solid, liquid, or gas • But 99% of all matter observed in the universe exists
as plasma, which is not common on earth • Plasma exists only at extremely high temperatures
such as those found on the sun or other stars • Bose-Einstein Condensate (BEC) - state of matter that
exist at extremely low temperatures, near -273°C
2/2/15
2
Kinetic Theory • Kinetic energy - energy an object has due to
its motion • The Kinetic Theory of Matter says that all
particles of matter are in constant motion – According to the theory the particles inside
a solid baseball are moving and the particles in the air the baseball travels through are moving too
Behavior of Gases • Similar to balls during a game of billiards
– Ball move in straight lines until it strikes the sides or another ball
– Transfers kinetic energy • Gas particles never rest
– Some move faster than others at average speed – Collide, slow down, speed up but kinetic energy
of the atoms remains the same • There are forces of attraction among
particles in all matter – But for gas particles which are apart and
moving fast the attractions are too weak to have an effect
Kinetic Theory of Gases • The constant motion of
particles in a gas allows a gas to fill a container of any shape or size 1. Particles in a gas are in
constant, random motion 2. The motion of one particle is
unaffected by the motion of other particles unless the particles collide
3. Forces of attraction among particles in a gas can be ignored under ordinary conditions
Behavior of Liquids • Have kinetic energy but have a
definite volume because the energy is lower so the atoms move slower than a gas at the same temperature
• Particles are also closely packed so the attractions between the particles affect the movement
• A liquid takes the shape of its container because particles in a liquid can flow to new locations
• The volume of a liquid is constant because forces of attraction keep the particles close together
Behavior of Solids • Like people sitting in a movie
theater – Stay in their seats (“fixed”) but
shift and move around in place • Solids have a definite volume and
shape because particles in a solid vibrate around fixed locations – Vibration is repetitive back-and-
forth motion • Strong attractions restrict
movement and keep each atom in a fixed location relative to its neighbors
top related