Who discovered the electron?
J.J. Thompson discovered the electron.
What was the name of Thompson's experiment?
Thompson's experiment: Cathode Ray Tube Experiment
What was Thompson's contribution to Atomic Theory?
Thompson discovered the existence of neutrons and the neutron's negative charge.l
Describe Thompson's Cathode Ray Tube Experiment.
1. Shoots a current through the Cathode Ray Tube.
2. Applied a magnetic field around the tube.
3. The current is bent toward the positive area.
4. This shows that the current is negative.
Who discovered the nucleus?
Ernest Rutherford discovered the nucleus.
What was the name of Rutherford's experiment?
Rutherford's experiment: Gold Foil experiment
What was Rutherford's contribution to Atomic Theory?
1. Discovers the nucleus.
2. Atom is mostly empty space.
3. Nucleus is small, dense, positive charge; located at the center of an atom.
Describe Thompson's Gold Foil Experiment.
1. Shoots positive charged particles at a piece of gold foil.
2. Most of the particles go straight through (because atom is mostly empty space).
3. Some particles were deflected.
4. Very few even bounced back.
Who were the four most important thinkers regarding modern Atomic Theory?
Democritus, Lavoisier, Proust, and Dalton were the four most important thinkers regarding modern Atomic Theory.
What was Democritus's contribution to Atomic Theory?
Democritus: all matter is composed of tiny invisible particles called atoms (means indivisible).
What was Lavoisier's contribution to Atomic Theory?
Lavoisier: Law of Conservation of Mass- "in ordinary chemical reactions, matter can neither be created nor destroyed, but changed.
What was Proust's contribution to Atomic Theory?
Proust: Law of Definite Proportions- "in a compount, elements combine in definite proportions to one another.
What was Dalton's contribution to Atomic Theory?
Dalton: Law of Multiple Proportions-
1. Matter consists of definite particles called atoms.
2. Atoms are indestructable. They can rearrange in chemical reactions but they do not themselves break apart.
3. Atoms of a particular element are indistinguishabl