Unit 1.2: Antoine Lavoisier and the

History of the Atom

Bell Work: September 2•Summarize the Law of the Conservation of Matter/Mass in two sentences•If you finish early, study for your quiz•Remind me about Good Things!

Lavoisier Video

•https://Lavoisier Law of Conservation of Mass Video

Definitions: Antoine Lavoisier Article

• Ferme Generale was a private company that collected taxes for the Crown• Phlogiston Theory was the theory that there was a substance called

phlogiston which was odorless, tasteless, colorless, and weightless. This substance was thought to be given off when the material containing this substance was burned. • Calx is the crumbly residue left over after a mineral or metal has

been heated.

Antoine Lavoisier Web•With the person sitting next two you (at your table of 4), write 2 facts from the biography on each of the four subtopics of the web.

Models of the Atom •With the person sitting next to you (in your table of 4) put

the atomic model cards in chronological order. • On a sheet of paper with both of your names on it, write

the following:• List the order of the models• Compare and contrast each of the models. What is the

difference between each one? What is similar about each one? Be extremely detailed in your explanations. Write in full sentences.• For each model, explain your reasoning for the placement of

the model. Be specific and descriptive. Write in full sentences.

Create an atomic Model Flip Chart

• Place your paper on your desk horizontally• Fold both sides towards

the center • Cut the flaps into thirds

horizontally• Label like the pictures

(leave room to write on the inside flaps)

Democritus Rutherford

Dalton Bohr

Thomson Present Model

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John Dalton Atomic Model

• September 1766-July 1844• He was an English chemist,

meteorologist, and physicist best known for reviving the atomic model and research into color blindness

John Dalton Atomic Model • Elements are made of extremely small particles

called atoms• Atoms of a given element are identical in size,

mass, and other properties. • Atoms cannot be subdivided, created, or

destroyed• Atoms of different elements combine in simple

whole number ratios to form chemical compounds• In chemical reactions, atoms are combined,

separated, or rearranged.

J.j. Thomson Discovers the electron

• Electricity enters the cathode and comes out the anode in a vacuum tube (no air in the tube)

• A beam of light called the “Cathode Ray” can be seen

• This ray can be repelled or attracted using magnets• Repel= negative side of

magnet• Attract = positive side of

magnet• This means that the ray

must be negative (opposites attract)

• Ray = 1000x lighter than Hydrogen atom • First subatomic particle!

• The electron was the first subatomic particle discovered

• Used a cathode ray tube

• Cathode Ray Tube Video