Kinetic Molecular Theory (KMT)
Kinetic Molecular Theory (KMT)
Kinetic Molecular Theory (KMT)
States of Matter Solid
Particles close together May only vibrate
Liquid Particles not as close together Particles may move past each other, but
attracted to each other Gas
Particles far apart Particles may move past each other, NOT really
attracted to each other
States of Matter Solid
Particles close together May only vibrate
Liquid Particles not as close together Particles may move past each other, but
attracted to each other Gas
Particles far apart Particles may move past each other, NOT really
attracted to each other
• Particles close together
• May only vibrate
• Particles close together
• May only vibrate
SolidSolid
Liquid• Particles not as close
together • Particles may move
past each other, but attracted to each other
Gas• Particles far apart• Particles may move
past each other, NOT really attracted to each other
Liquid• Particles not as close
together • Particles may move
past each other, but attracted to each other
Gas• Particles far apart• Particles may move
past each other, NOT really attracted to each other
LiquidLiquid
GasGas
Molecules Cause Pressure
Kinetic Molecular Theory
Particles of matter are ALWAYS in motion
Volume of individual particles is zero. Collisions of particles with container
walls cause pressure exerted by gas.
Particles exert no forces on each other.
Average kinetic energy µ Kelvin temperature of a gas.
Measuring Pressure
The first device for measuring atmospheric pressure was developed by Evangelista Torricelli during the 17th century.The device was called a “barometer”
Baro = weight Meter = measure
An Early Barometer
The normal pressure due to the atmosphere at sea level can support a column of mercury that is 760 mm high.
PressureIs caused by the collisions of molecules with
the walls of a container is equal to force/unit area SI units = Newton/meter2 = 1 Pascal (Pa) 1 atmosphere = 101,325 Pa 1 atmosphere = 1 atm = 760 mm Hg = 760
torr