Chap 4
Extra help and Study Guide
ØAll matter is composed of tiny particles
(molecules) that are in constant motion
ØIn the solid state an attractive force (a
pull (from inside the molecule) that makes them want to stay with each other)
between these particles holds them in place to vibrate
o They have a defined volume & shape
Ø Particles in the liquid state have defined volumes
but are free to move about in the liquid
o they have no defined shape
ØThermal energy is the total energy
of the particles in a sample of matter
ØTemperature is the average
kinetic energy of the particles in a sample
ØAn object gains thermal
energy when it changes from:
o a solid
to a liquid = melting
o
a liquid to a gas = vaporization
Ø An object loses thermal energy when it changes
from:
o a gas to a liquid = condensation
o a liquid to a solid =
freezing (only called that with water really) but the action is the
same
ØPressure is force divided by area
ØFluids exert a buoyant force the upward direction
on object immersed in them
ØAn object will float in a fluid that is more dense
than itself