Download NOTES-Chapter 12

NOTES-Chapter 12
Thermal Energy
• Heat is defined and expressed by
the Kinetic Molecular Theory of
heat.
•This theory states that
all matter is made up of
tiny particles which are
constantly in motion.
•Heat is the internal energy
which is transferred from bodies
of higher internal energy to
bodies of lower internal energy.
Heat does work and work
produces heat.
•Temperature and heat are
different. Temperature is a
measure of the average
kinetic energy of the
molecules of the substance.
•Temperature is measured
with a thermometer due
to the expansion &
contraction of the liquid
in the scale.
•The metric scale is the
Celsius scale & it has 2
fixed points:
•Freezing point of water
•Boiling point of water
•Freezing point is 0 degrees
and boiling point is 100
degrees.
Celsius and Fahrenheit can be
converted back and forth….
With formulas.
F= C(1.8) + 32
C=(F-32) / 1.8
•The random motion of
molecules is thought to
approach zero at -273
degrees Celsius----average
kinetic energy is zero.
• This temperature is called
absolute zero and is measure by
the Kelvin scale.
• Celsius can be converted to
Kelvin by the following formula:
• K = degrees C + 273
• Heat Travels from hot to cold.
• It travels until it reaches thermal
equilibrium.
• The unit of heat measurement
is the calorie—it is the
amount of heat needed to raise
the temperature of 1 gram of
water 1 degree Celsius.
• Bigger unit is the Kilocalorie.
•Specific Heat of a substance
is the amount of heat
needed to raise the
temperature of a unit mass
of that substance through
one degree.
• Specific Heat is expressed in
cal/g(degreeC)
• And are specific for each type
of substance.
• The quantity of heat gained or
lost by a mass as it changes
temperature is determined by
the mass, change in
temperature, and specific heat.
• H = m c (Delta t)
• States of Matter
Heat Transfer Methods
Insulators and Conductors
Phase Changes
Laws of Thermodynamics