Chapter 2: The Human Organism
and the Power of Energy
What is energy?
• You may sometimes feel like you are having
too much work and not enough energy to do
the work!
 Energy is the Capacity to do work or to
produce change.
– Homework induces a change in your brain:
connections between neurons are formed,
therefore it requires energy.
Unit of energy:
The standard unit of energy is the ___________
Joule (J) .
One Joule represents
the energy needed to
lift an object weighing
one Newton (N) to the
height of one meter
(m).
On earth 1N = 100 g
1 Joule
100
100gg
1 meter
100
100gg
Calorie
15°C  16°C
Thermal energy
• The energy, that is contained in the agitation
of the molecules.
Thermal Energy
Thermal energy
• The energy, that is contained in the agitation
of the molecules.
• The amount of thermal energy, that a
substance contains, depends on the degree of
agitation of its molecules (temperature)…
• … and on how much substance there is.
 Which contains more thermal energy?
80°C
✓
50°C
Examples of work or change induced
by thermal energy.
• Melting of snow.
• Lifting of a hot air balloon by
heating the air.
Radiant energy
• … is the energy contained in and transported
by electromagnetic waves
Radiant Energy
Electromagnetic waves:
 transport energy from one place to another.
• The amount of transported energy depends on
the wavelength and the quantity of radiation.
• The shorter the wavelength of a given number
of waves the more energy the wave can
transport.
Radiant Energy
Examples of work or change induced
by radiant energy.
• Food is heated by
microwaves
• Getting suntanned or
burned from ultraviolet
rays
Density
• Mass per unit of Volume
• Measured in g/mL
𝑚
𝜌=
𝑉
Mechanical energy
• .. Is the energy that results from the speed
_____of
relationship to
mass and its _____________
an object, its _____,
its surrounding
_____________.
Mechanical Energy - speed
fast
slow
Mechanical Energy - mass
light
heavy
Mechanical Energy - position
More
Less
Mechanical energy
• .. Is the energy that results from the speed
_____of an
object, its _____,
relationship to
mass and its _____________
_____________.
its surrounding
> The greater the speed the greater the
mechanical energy.
> The greater the mass the greater the
mechanical energy.
> The higher the object the greater its mechanical
energy.
Examples of work or change
induced by mechanical energy.
• Crater caused by an asteroid.
• Electricity generated by spinning a turbine
(hydro + wind).
• Dent in a car from a crash.
Chemical Energy
• … is the energy stored in the bonds of a
molecule
• Energy is stored when bonds are formed …
• … and can only be released when bonds are
broken and reorganized.
Chemical Energy
Photosynthesis
CO2 + H2O
Chemical Energy
Respiration
CO2 + H2O
Chemical Energy
• … is the energy stored in the bonds of a
molecule
• Energy is stored when bonds are formed …
• … and can only be released when bonds are
broken and reorganized.
• The amount of energy stored in a molecule
depends on the strength and the number of
bonds.
Examples of work or change
associated with chemical energy.
• COMBUSTION of gasoline 
Driving of a car.
• PHOTOSYNTHESIS:
light energy  chemical energy
• CELLULAR RESPIRATION:
chemical energy  animals grow
move and think.
Other Forms of Energy
Energy Form
Energy Source
Solar Energy
Sun
Electrical Energy
Power Station
Wind Energy
Wind
Sound Energy
Sound Waves
Hydraulic Energy
Moving Water
Nuclear Energy
Nucleus of an atom
Energy transfer
• Energy transfer is the movement of energy
from one place to another:
Heat / Heat transfer
HEAT is the transfer of thermal energy from one place to
another.
Energy
• The molecules in the drink transfer thermal energy to the
cup  the cup gets warm.
• The molecules of the cup transmit vibration energy to the
molecules of our skin.
•  Agitation of the molecules in our skin feels warm to us.
Transformation of energy
• The transformation of energy is the change of
one form of energy into another.
light
chemical
chemical
electrical
mechanical chemical
thermal
mechanical
Terms to Know
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•
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•
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Matter
Pure Substance
Compound
Element
Molecule
Particle
Characteristic Chemical
Property
• Characteristic Physical
Property
•
•
•
•
•
•
•
•
•
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Mixture
Heterogeneous
Homogeneous
Colloid
Solution
Solute
Solvent
Solubility
Concentration
Dilution
Particle Model
• Matter is made up of particles that are in
constant motion.
• Particles in a solid are very close together and
move very little.
• Particles in a liquid are close together and move
more than the particles in a solid but less than
particles in a gas
• Particles in a gas are very far apart and move a
lot.
MATTER
MIXTURES
heterogeneous
PURE SUBSTANCES
homogeneous
compounds
elements
Contain only one
type of particle
Suspension
Colloid
Solution
?
✗
Separation Techniques
•
•
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Decantation
Centrifugation
Filtration
Evaporation
Distillation
Chromatography
Characteristic physical properties
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•
•
•
Melting Point
Boiling Point
Density
Solubility
• Do not change the substance during the
identification process.
Chemical characteristic properties
Gas
Liqid
Hydrogen
Water
Burning splint test Cobalt chloride
paper
 explosion
 turns pink
Oxygen
Acid /Base
Glowing splint test Litmus paper
 re-ignition
 acid > red
base > blue
Carbon dioxide
Limewater test
 gets cloudy
Certain metal
salts
Flame test
 Flame will take
a characteristic
colour depending
on the metal
Which purification technique would be least
useful in separating a mixture of two liquids?
a) Decantation
b) Filtration
c) Centrifugation
d) Distillation
Which of the properties in the table below
can help us identify the unknown substance
tested?
Property
Results
Boiling Point
65°C
Mass
79g
Volume
100mL
Colour
Clear
Reaction to litmus paper
No change
Identify the following as Homogeneous or
Heterogeneous
a) A bowl of Cereal: ______________________
b) A Toonie: __________________
c) Chocolate Milk: __________________
d) Blood: ___________________