*Energy: is the ability to do work or to produce change. Ex: lifting arm or melting snow.

*SI expresses the unit of measure for energy in joules(J)*1 J is the amount of energy needed to lift an object weighing 1

newton (N) to a height of 1 metre.Forms of Forms of EnergyEnergy Thermal Energy: the energy that comes from the random

motion of particles of a substance. Ex: melting snow, steam train, hot-air balloon

Mechanical Energy: Results from the speed of an object, its mass and its relationship to its surroundings. Ex: a rock held at different heights, wind energy, hydraulic energy, creation of a crater.

250 ml50º C

500 ml50º C

Both have the same temperature, but the second beaker contains twice the amount of thermal energy.

Factor Factor variation Result

Number of particles More particles Increased thermal energy

Fewer particles Reduced thermal energy

Temperature Higher temperature Increased thermal energy

Lower temperature Reduced thermal energy

Properties affecting Thermal EnergyProperties affecting Thermal Energy

*Radiant Energy: contained in and transported by electromagnetic waves.*Electromagnetic waves

transport energy from one place to another.

*Quantity depends on wavelength and amount of radiation. Shorter the wavelength the more energy transported.

*Ex: light, UV rays in tanning, X-Ray images, radiation therapy

*Chemical Energy: stored in the bonds of molecules.

*Energy in reserve. Amount is dependant upon strength & number of bonds. Stronger bonds contain more energy.

*Energy is released when the bonds are broken. Ex: burning a candle, combustion of gasoline in car, cellular respiration.

*Transformation of Energy: is the changing of energy from one form to another.*Ex: burning a log: chemical energy stored in wood is transformed to radiant energy (light) and thermal energy (particle movement).

*Energy transfer: is the movement of energy from one place to another.*Movement of energy from burning log to surroundings; heat.

*Heat: transfer of thermal energy from one place to another. *Travels from place of higher temperature toward lower temperature.

*Energy transfer and transformation can result in both chemical and physical changes.

1. Changes of 1. Changes of StateState 3 states of matter: solid, liquid and gas 3 states of matter: solid, liquid and gas

The transformation from one state or The transformation from one state or phase to another. phase to another.

H2O(s) ↔ H2O (l) (freezing) (melting)Ex:

CHANGES OF STATES/PHASE CHANGES

1) Melting/Fusion: Solid → Liquid Ex: Ice water2)Freezing/Solidification: Liquid → Solid

Ex. water Snow flakes3)Vaporization (boiling & evaporation): Liquid → Gas

Ex: water steam

Phase changes: The change in thermal energy (addition or removal of heat) changes the forces of attraction causing the particles to move closer to, or further from, one another resulting in a change of state.

4) Condensation: Gas → Liquid Ex: Steam water

5) Sublimation: Solid → Gas*The solid does not melt to liquid,Instead turns directly to gas.Ex. Dry Ice [CO2 (s)] to CO2 (g)]

6) Deposition: Deposition: Gas → SolidThe gas cools but skips condensation and turns directly to a solid. Ex: Snow, frost, hailEx: Iodine vapour -> Solid Iodine

*The creation of a solution by a solute dissolved in a solvent.

*Ex: sugar in water, carbon in iron.

*Normally involves the absorption or release of energy.*When dissolution releases energy temperature

*When dissolution absorbs energy temperature3. Deformation3. Deformation Changing the shape of a material. Some are reversible (stretching a coil), some are

permanent (tearing a sheet of metal). Involves an energy transfer, usually more than one.

Ex: jumping on a trampoline (mechanical to elastic which is a reversible deformation)

*Involves the production of one or more new substances.*One or more substances (reagents) react to make new substances (products)

*Bonds between reagents change and reform making new substances.

*Changes the nature and characteristic properties of matter.*Law of conservation of mass: all matter is transformed none is created or destroyed, # of atoms remains constant.

Telling difference between chemical and physical changes:

-The release of a gas -Greater changes of heat-Generation of light -Change of colour-Formation of a precipitate –Change in mass

Chemical change:2Na(s) + 2H20 (l) → 2NaOH (aq) + H2(g)

Chemical Reactions can combine elements to make compounds

(1. synthesis reaction)

OR

Chemical Reactions can break apart compounds into its elements

(2. decomposition reaction)

*The transformation of complex molecules into simpler molecules or into atoms. Is the opposite of synthesis.

*Reaction where a compound separates into two or more compounds or elements. (AB = A + B)

*The chemical energy of a molecule is released or transformed into other forms of energy. Ex: glycogen decomposing into glucose releases thermal energy, electrolysis of H2O uses energy

The formation of a complex molecule from atoms or simpler molecules. Ex: H2 reacts with O2 to form H2O.

Is a chemical reaction that either absorbs or releases energy.

Reaction where 2 or more reactants combine to form a new product ( A + B = AB)

Photosynthesis absorbs energy: 6CO2 + 6 H2O + energy C6H12O6 + 6O2

Utilizes radiant energy to form stored energy as glucose. 2.Decompositio2.Decompositionn

*Makes a new substance

*Sign of a chemical change

*Increase in mass

*Ex.

*Ex.

If you see mass, the ONLY thing

you know is that a compound was

made!!!

+

+

*Two or more substances produced

*Sign of a chemical change

*Decrease in mass

*Ex.

*Ex.

If you see mass, the

ONLY thing you know is

that you started with

a compound!

+

+

*Is a chemical reaction involving oxygen in the air or a substance with similar properties to oxygen. Ex: iron rusting, banana ripening, fire, cellular respiration (opposite of photosynthesis).

*4 Fe + 3 O2 2 Fe2O3 +energy

*Combustion is a form of oxidation that releases a large amount of energy.

*Occurs when two solutions are combined and an insoluble or less soluble substance forms. Ex: when doing the Fehling reagent test for carbohydrates the presence of certain carbohydrates formed a precipitate.

*Requires very little energy.

4. 4. PrecipitationPrecipitation