Types of Chemical Change Oxidation Combustion Cellular Respiration Photosynthesis

Oxidation Materials oxidize when they react with oxygen in the air Rusting (corrosion) is a form of oxidation Iron in air will form iron oxide (rust) Fe + O2  FeO2 (iron oxide)

Presence of air, light, water and salt can accelerate oxidation

Iron Oxide (Rust)

Copper Oxide

To prevent or slow oxidation… Galvanize the metal (coat in Zinc) Oil coating Rust proofing Water proofing Add preservatives to food which may oxidize

Combustion A form of oxidation that releases a large amount of energy Burning wood, cellular respiration Burning fossil fuels Principal of the “internal combustion engine”

Internal Combustion Engine

3 conditions to promote combustion Fuel (wood, propane, oil, gas etc.) Oxidizing agent: causes the fuel to react (oxygen in the air is most common) Ignition temperature: minimum temperature which combustion starts. Different for each type of fuel.

Triangle of Fire

3 types of combustion Rapid: fire, explosion, car engine Spontaneous: ignites without any outside energy source (eg: some forest fires, oil coated rags) Slow: decomposition, fermentation, metal corrosion

Cellular Respiration A chemical change in which glucose (sugar) and oxygen are used to generate energy Essential to life A form of slow combustion Allows organisms to survive and function

Glucose + oxygen  carbon dioxide + water + energy

Photosynthesis Chemical change that produces glucose and oxygen from solar energy, carbon dioxide and water Essential for plant growth and human survival

Photosynthesis