Transcript Notes 2-3
Notes 2-3
Energy and Matter
ENERGY
Who
remembers
the
definition of
Energy?
The
Ability to
do
WORK!
ENERGY
All chemical and physical changes
include a change in energy
Law of Conservation of Energy
Energy is neither created nor
destroyed
It is only transformed (changed from
one form to another)
Forms of Energy
Forms of energy that include changes in
matter are: Thermal Energy, Chemical
Energy, Electromagnetic Energy, and
Electric Energy
Thermal Energy
Temperature = average
Endothermic Change =
energy of random motion
of particles of matter
Thermal Energy = total
energy in all particles in
an object
Thermal energy is related
to temperature because
the energy always flows
from warm matter to cool
matter
energy is absorbed
Ex: Melting
Exothermic Change =
energy is released
Ex: Combustion
Chemical Energy
Stored in Chemical Bonds between atoms
Bonds are broken and new bonds formed
Ex: in foods, gas for cars, cells
Usually involve transformations between chemical energy
and thermal energy, like when burning a match
Electromagnetic Energy
Travels through space as waves
Ex: Visible light, radiowaves, microwaves, x-rays, UV rays,
infrared rays
Chemical changes can give off light (electromagnetic
energy)
Microwaves thaw frozen food (physical change)
Electrical Energy
Energy of electrically charged particles moving from one
place to another
Ex: electrons move from one atom to another in many
chemical changes.
Ex: using electrolysis to separate water molecules into
oxygen gas and hydrogen gas
Potential Vs Kinetic
POTENTIAL ENERGY:
KINETIC ENERGY:
Energy waiting to
Energy of Motion
be used
Ex: Food you eat
(Energy being
used)
Ex: You taking
notes!
Transforming Energy Example 1:
Burning
-Chemical change
that transforms
chemical energy and
releases it as thermal
energy (heat) and
electromagnetic
energy (light)
Transforming Energy Example 2:
Photosynthesis
-Plants transform
electromagnetic
energy from the sun
into chemical energy
(sugar for plants)
Transforming Energy Example 3:
You Try!
There is potential energy
What energy
in the food you eat.
Your cells transform food
into chemical energy your
body can use.
Chemical energy is
transformed to kinetic
energy of moving
muscles and thermal
energy given off as heat.
transformations occur
when you ride a bike?