PHYSICAL OR CHEMICAL CHANGE

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PHYSICAL OR CHEMICAL CHANGE
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CHEMICAL CHANGE

• CHEMICAL CHANGE is any change that results in
  the formation of new chemical substances.
• Chemical change involves the making or breaking
  of bonds between atoms

molecule
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EXAMPLES OF CHEMICAL CHANGE

• Sun tanning (melanin vitamin D form)
• Iron rusting (iron oxide forms)

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TEN SIGNS OF CHEMICAL CHANGE

• Bubbles appear
• A precipitate forms
• A color change occurs
• The temperature changes
• Light is given off

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TEN SIGNS OF CHEMICAL CHANGE(CONT.)

• A change in
• 6. Volume
• 7. Electrical conductivity
• 8. Melting or boiling point
• 9. Smell
• 10. Any distinctive chemical or physical property

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PHYSICAL CHANGE

• PHYSICAL CHANGE rearranges molecules but
  doesnt affect their internal structure

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EXAMPLES OF PHYSICAL CHANGE

• Boiling water
• Dissolving kool-aid in water

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INVISIBLE INK AND HEAT

• What are your conclusions?
• Physical or Chemical Change?
• Evidence?

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INVISIBLE INK

• lemon juice heat oxidation
• Chemicals in the air react with chemicals in the
  lemon juice to form a brown substance.
• heat speeds up the reaction

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STATION ASTEEL WOOL OXYGEN

• What are your conclusions?
• Physical or Chemical Change?
• Evidence?

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STATION ASTEEL WOOL OXYGEN

• 4Fe 3O2 2Fe2O3
• iron oxygen FORMED rust (new substance)
• This process is called oxidation.

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STATION BBAKING SODA VINEGAR

• What are your conclusions?
• Physical or Chemical Change?
• Evidence?

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STATION BBAKING SODA VINEGAR

• CH3COOH NaHCO3 CH3COONa H2O CO2
• acetic acid sodium bicarbonate
• FORMED
• sodium acetate water carbon dioxide

(vinegar)
(baking soda)
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STATION CCALCIUM CHLORIDE WATER

• What are your conclusions?
• Physical or Chemical Change?
• Evidence?

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STATION CCALCIUM CHLORIDE WATER

• CaCl2 2H2O Ca(OH)2 2HCl
• calcium chloride water
• FORMED
• calcium hydroxide hydrogen chloride

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STATION DPLASTER OF PARIS WATER

• What are your conclusions?
• Physical or Chemical Change?
• Evidence?

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STATION DPLASTER OF PARIS WATER

• CaSO4 H2O H2O CaSO4 2H2O
• Plaster of Paris is partially dehydrated gypsum.
• In order to be hard, gypsum needs to be complete
  hydrated.

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STATION EEGGSHELLS VINEGAR

• What are your conclusions?
• Physical or Chemical Change?
• Evidence?

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STATION EEGGSHELLS VINEGAR

• calcium carbonate acetic acid
• FORMED
• calcium ion water carbon dioxide

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STATION FCOPPER SALT WATER

• What are your conclusions?
• Physical or Chemical Change?
• Evidence?

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STATION FCOPPER SALT WATER

• Copper atoms join with oxygen atoms from the air
  and chlorine atoms from the salt water to form a
  blue-green compound called malachite. This is
  called patina.
• Cu O Cl patina

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STATION GPENNIES VINEGAR
What are your conclusions? Physical or Chemical
Change? Evidence?
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STATION GPENNIES VINEGAR

• Old pennies are covered with copper oxide
• made when copper in the penny reacts
• with oxygen from the air.
• When soaked in vinegar, the acid in the vinegar
  reacts with the copper oxide
• and the dark coating dissolves.

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What are your ideas?

• Student examples of physical change
• Student examples of chemical change