1. The Human Organism and the Power of Energy
Chapter 2
The Human Organism and the Power of Energy

2. Energy Types and Transformations
Lesson 2.1
Energy
Types and Transformations

3. ENERGY ENERGY is the capacity to do work or cause a change
There are many forms of energy
Some forms of energy are listed on the next slide
All forms of energy can be measured in JOULES
The main unit of energy is the Joule (J).
A Joule is the amount of energy it takes to lift a Newton (about 100g) one metre.
1000 Joules = 1 kilojoule (kJ)

4. These are the 4 energy forms that we will study in more detail.
Some Forms of Energy
Energy Form
Energy source or example
Solar Energy
Energy from the sun or sunlight, eg. Solar panel
Elastic Energy
Energy from springs or elastics, eg. Watchsprings
Electrical Energy
Energy generated by electrical stations or batteries
Wind Energy
Energy from moving air, eg. Windmill
Sound Energy
Energy from sound, eg. Stereo speakers
Hydraulic Energy
Energy from moving water, eg. Waterfall or dam
Thermal Energy
Energy from hot, fast-moving molecules, eg. fire
Radiant Energy
Energy from electromagnetic radiation, eg. Light, heat
Chemical Energy
Energy from chemical bonds, eg. Food energy,
Mechanical Energy
Energy from moving objects, eg. Vehicles.
These are the 4 energy forms that we will study in more detail.

5. As you can see, even in solids, the molecules vibrate a bit
THERMAL ENERGY
Thermal energy comes from the random motion of the particles (Temperature of molecules) that make up a substance and the amount of particles (mass).
The faster the molecules of a substance move, the hotter the substance seems to us.
Really fast
molecules
can
even
make
flames!
Cold Warm Hot
As you can see, even in solids, the molecules vibrate a bit

6. RADIANT ENERGY
Radiant Energy is contained in, and transported by electromagnetic waves
Light is the most obvious form of radiant energy
The shorter the wavelength the greater the energy
Other forms of radiant energy include:
X-Rays
Radio Waves
Ultraviolet Rays
Infra-red Radiation
(radiated heat)
Gamma rays, cosmic rays
(powerful radiation)

7. CHEMICAL ENERGY
CHEMICAL ENERGY is stored in the bonds of molecule or by forming bonds.
Like the energy in gasoline, or wood that you burn, or any other form of fossil fuel.
Also, the energy used by life, such as the energy in food, is chemical energy.

8. MECHANICAL ENERGY
MECHANICAL ENERGY results from the speed and mass of an object, and from its relationship to its surroundings.
In other words, mechanical energy comes from the movement of objects.
Falling objects, moving vehicles, mechanical devices and spinning wheels all have mechanical energy.

9. ENERGY TRANSFORMATION
ENERGY TRANSFORMATION is changing energy from one form to another
Examples:
Radiant  to  Thermal (sun warms ground)
Chemical  Radiant  Thermal (burning causes light & heat)
Radiant  to  Chemical (photosynthesis)
Heat (thermal energy)
Radiant
Radiant (light)
Flame (radiant energy)
Food (chemical)
Log (chemical energy)
Thermal (heat)

10. Assignments on Energy Types and Transformations
Textbook pp.
Workbook pp.23 to 26

11. How energy causes changes in matter
Lesson 2.2
How energy causes changes in matter

12. Changes and Energy
Energy can cause changes in matter, and changes in matter can produce energy.

13. Types of Changes:
Two Types of Changes
Physical Change
Chemical Change

14. Physical Change:
Does not change the chemical composition of a substance. It does not affect the nature or characteristic properties of the substance.
Process is sometimes* reversible
for changes of state
Ex. Crumpling & smoothing out paper
Ex. Freezing water and thawing ice
Ex. Sublimation – from solid to gas (ex. dry ice (CO2) or iodine)
*there are a few physical changes that are difficult to reverse.

15. Physical Change Key Words: Crush/PulverizePhysical change
Tells you a
physical change
occurred
Physical Change Key Words:
Crush/PulverizePhysical change
Melt (Fusion)Physical change
Evaporation Physical change Condensation Physical change Sublimation Physical change
Solidification Physical change
Dissolve Physical change

16. Energy and Change of State (some people say “Phase” instead of “State”)
Adding thermal energy to an object makes its particles (ie. Atoms or Molecules) move faster.
If the particles move fast enough, the substance may change state, going from solid to liquid or from liquid to gas.
Change of state is a PHYSICAL change caused by changing the amount of thermal energy in a substance

17. Physical Changes of State
Absorbs Energy
GAS
Releases Energy
They just move faster (or slower)
DEPOSITION (solid sublimation)
SUBLIMATION (gaseous)
When
a substance
changes state
it is always a
physical change! Its
molecules don’t change
VAPORIZATION (evaporation)
CONDENSATION (liquid)
FUSION (Melting)
SOLID
LIQUID
SOLIDIFICATION(Freezing)

18. Chemical Changes:
Changes the chemical composition or make-up of the substance
New substances are formed with new properties
Not easily reversible
(Reversible only through chemical means or reactions)
Rust

19. Signs of Chemical Changes:
Tells you a
chemical change
occurred
Signs of Chemical Changes:
Formation of a new gas when two substances mix.
Formation of a precipitate from mixing two solutions.
A significant change in colour when materials react.
Release of heat &/or light when materials are mixed
Increase or decrease in mass

20. Be Careful! Pay attention to the “when” part of each clue.
Eg. “It is a chemical reaction if gas is released when two materials mix”
One of these is definitely a chemical change, the others are not:
1) Gas bubbles are released when a pop bottle is opened
2) Gas bubbles are released when vinegar and baking soda mix.
3) Gas bubbles are released when water boils.
#2 is the chemical change. #1 is not, since the release of gas is due to pressure change. #3 is not, since it is a change of state (liquid to gas)

21. Be Careful! Pay attention to the “when” part of each clue.
“It is a chemical reaction if a significant change in colour occurs when materials react.”
One of these is definitely a chemical change, the others may not be:
1) Base added to phenolphthalein changes it from clear to bright purple-pink.
2) Wet blue jeans look darker than dry ones.
3) Mixing yellow and blue paint makes green paint.
#1 is the chemical change. #2 is not, since the colour change is not significant. #3 is not, since it is a simple blending of existing colours, not a reaction.

22. Chemical Change: Synthesis
The formation of a complex molecule out of atoms or simpler molecules.
Reactants Products
Synthesis H H H H O O H H O O H H
become
O H2
Three simple molecules
2 H2O
Two more complex molecules

23. Chemical Change: Decomposition
When complex molecules are transformed into simpler molecules or atoms Al Al O O O O O O Al Al O O Al Al O O Al Al O O
Become...
4 Al O2
Seven simpler molecules or atoms
2 Al2O3
two complex molecules

24. Chemical Change: Oxidation
When oxygen combines with a material to change it.
rusting of iron or corrosion of any metal is an example of slow oxidation.
Combustion or burning is an example of rapid oxidation.
Note: This type of oxidation is also a synthesis. Some oxidations may be decomposition.
4 Fe + 3O2  2Fe2O3
C + O2  CO2
Fuel

25. Chemical Change: Precipitation
In chemistry, precipitation is the formation of a solid that is insoluble following the mixing of two solutions
In other words, if you mix two transparent solutions and produce a cloudy mixture that eventually settles to form a powdery solid, that is a chemical precipitation.
Don’t mix up chemical precipitation with meteorological precipitation, which is rain or snow.
Transparent
Cloudy
Transparent

26. Examples: Physical Change Sublimation Freezing Condensation
Evaporation
Pulverization (crush)
Solidification
Dissolving
Chemical Change
- Burning
- Neutralization
- Combustion
Oxidation
Synthesis
Decomposition
Precipitation

27. Ex #1: Which of the following are examples of physical changes?
1. Melting Butter
4. Crushing Rock
2. Rusted Car
5. Condensation
3. Dissolving Sugar in Tea
6. Burning Wood

28. Ex #2: Which of the following are examples of chemical changes?
1. Cooking an egg
4. Freezing Rain
2. Rotting food
5. Burning a candle
3. Sublimation of Dry Ice
6. Crumpling Paper

29. Ex #3: Chemical Change Physical Change
Where did a chemical change occur? A physical change?
You carry out the following steps of an experiment & record your observations.
Ex #3:
1. You place a powder in a test tube
2. You heat the test tube. You notice that a colorless gas & a copper-colored liquid are produced.
3. You collect the copper-colored liquid & cool it. It becomes a solid.
Chemical Change
Physical Change

30. Assignments on Physical and Chemical Changes
Read Textbook pp. 43 to 58, q. 9-15
Do Workbook pp (energy)
Do Workbook pp (changes)

31. Chapter End Questions Textbook pages 59 to 61
Write down the date of the chapter 2 test in your agenda or homework book.