Atomic Theory Flashcards
Democritus and Leocipidus View:
Propose idea of atoms
Matter composed of small, invisible parts
Particle model of matter
Plato and Aristotle View
Most widely accepted
Matter infinitely divisible
Continuous model
Pierre Gassendi
Translator of Moorish texts following dark ages that leads to rediscovery of science in west.
Robert Hook
Developer of Kinetic Theory of Gases to explain gas laws
Joseph Proust
Found that every material had a fixed relationship by mass between the elements. Creator of law of definite proportions.
Antoine Lavoisseer
Creator of the law of conservation of matter.
Law of Conservation of Matter
Matter is not created nor destroyed. It only changes form.
John Dalton
Creator of the law of multiple proportions.
Law of Multiple Proportions
For substances made of the same elements, there is a unique, fixed relationship between the elements for each.
Amedeo Avogadro
Introduces the modern use of the terms atom and molecule. Hypothesizes that all gases of the same volume at the same conditions will have equal numbers of particles.
William Crookes
Inventor of the cathode ray tube. Proved that beam of light is actually a stream of negatively charged particles.
E. Goldstein
User of cathode ray tube to discover a beam of positively charged particles
JJ Thompson
Names negatively charged particles electrons and finds that they are the same regardless of the cathode used.
Thompson’s Model of Atom: Plum Pudding Model/Chocolate Chip Cookie Model
Atoms are the main, positively charged part of the jelly or cookie, and the electrons are the negatively charged particles embedded within the jelly or cookie. There must be enough positive charge to cancel out the negative charge.
Ernest Rutherford
Challenger of Thompson’s model with Niels Bohr and Hans Geiger.
