-
201
Aristotle
What: Made of the 4 elements. (fire, water, earth, air)
Had 4 qualities (hotness, dryness, coldness, wetness)
2 forces (conflict, harmony)
How: Developed it. People believed it for years to come. -
220
Democritus
Proposed the existence of an ultimate particle.
Used "atomos" to describe the particle. -
John Dalton
What: Atoms are tiny, indestructible particles with no internal structure.
How: Through discorse. -
J.J. Thomson
What: Electrons embedded in a spehere of positive electic charge.
How: Discovered it. -
The Curies
Pierre Curie and his wife Marie Curie stated that radioactive materials cause atoms to break down spontaneously, releasing radiation in the form of energy and subatomic particles. -
Hantaro Nagaoka
What: Has a central nucleus. Moves in orbits like rings around Saturn.
How: Developed it. -
Ernest Marsden
Worked with Hans Geiger under Ernest Rutherford.
Worked with Rutherford on gold foil experiment. -
Ernest Rutherford
What: An tom has a dense; positively charged nucleus. Electrons move randomly around the nucleus.
How; Published. -
Nies Bohr
What: Electrons move in speherical orbits at fixed distances from the nucleus.
How: Evidence is discovered years later. -
Louis de Broglie
What: Moving particles like electrons have some properties of waves.
How: Proposes. Evidence is collected years later. -
Erin Shrodinger
Developed the equation currently used to understand atoms and molecules. (Shrodinger Equation) -
Werner heisenberg
Asserted the uncertainty principle of quantum theory.
Heisenberg was awarded the 1932 Nobel Prize in Physics for the creation of quantum mechanics -
James Chadwick
What: Existence of neutrons. Nuclei contain neitrons and positively charged protons.
How: Comfirmed it.
