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?