1. Playing with fire!

2. Part 1 - Phlogiston Theory
True for the candle in the jar?
Johann Joachim Becher

3. Getting the fire started – testing Phlogiston Theory
Burning Magnesium and paper then weighing them
Calculating mass of magnesium or paper in the evaporating basin

4. DO NOT LOOK DIRECTLY AT THE MAGNESIUM STRIP WHEN BURNING!
Safety
DO NOT LOOK DIRECTLY AT THE MAGNESIUM STRIP WHEN BURNING!

5. Part 2 – Why was Phlogiston Theory incorrect?
What was the appearance of the magnesium before it was burned?
What was the appearance of the magnesium after it was burned?
Identify 2 things that were released from the magnesium and paper when placed in the flame.
If ‘Phlogiston’ (from phlogiston theory) was a substance that was thought to be released from matter when burning, would you have expected the weight of the magnesium strip and paper to have increased (weigh more) or decreased (weigh less)?
Do your results support the Phlogiston theory? If not, what do you think may have happened? (Clue: The magnesium has reacted with another element to form a compound)

6. Antoine-Laurent Lavoisier
Joseph Priestley
Antoine-Laurent Lavoisier

7. Lavoisier's Theory
The brief history of Joseph Priestley (discoverer of oxygen) and Antoine-Laurent Lavoisier (father of chemistry) and their contribution to science
Priestley and Lavoisier both worked on experiments on gases
Priestley published his work on ‘dephlogisticated air’ (before Scheele): found this dephlogisticated air’ contributed to making a flame more intense and shared his ideas with Lavoisier
Lavoisier studied into the gas further and did more experiments, eventually leading him to believe that it was the ‘dephlogisticated air’ that combines with the flame during combustion, forming a new compound (therefore magnesium will be heavier)
“What might this ‘dephlogisticated air’ be?”

8. Part 3 – Combustion Lesson Summary Worksheet

9. The Fire Triangle

10. Homework Priestly and Lavoisier Worksheet
Simulation: (combustion reaction game)
Chemical Reactions: Combustion Worksheet

11. Antoine Lavoisier and his theories on corrosion
Next lesson
Antoine Lavoisier and his theories on corrosion

12. What do you see? http://theshadowlands.net/spon.htm