Chapter 1 The history of the atom
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Chapter 1 The history of the atom Date Name Theory Representation 442 BC 4th century BC Democritus Aristotle Invisible particles called “atomos” 5 elements: earth, wind, water, fire, and aether ∅ 1805 Dalton Billiard Ball: atoms are solid spheres 1897 Thomson Plum Pudding model: electrons are embedded in a cloud of positive charge 1911 Rutherford Planetary model: atoms consist of a small dense center fill with positive charges (the nucleus), electrons are orbiting around the nucleus 1914 Bohr Energy Level model: electrons can only have certain fixed energies; they can jump from a level to another one. 1926 Schrödinger Electron cloud: Electrons don’t move in orbits (or in a set path). He stated that they move in waves, and they have no exact location. 1932 Chadwick Discovered the neutron
Transcript of Chapter 1 The history of the atom
Chapter 1 The history of the atom
Date Name Theory Representation
442 BC 4th century
BC
Democritus
Aristotle
Invisible particles called “atomos” 5 elements: earth, wind, water, fire,
and aether ∅
1805 Dalton Billiard Ball: atoms are solid spheres
1897 Thomson Plum Pudding model: electrons are
embedded in a cloud of positive charge
1911 Rutherford
Planetary model: atoms consist of a small dense center fill with positive charges (the nucleus), electrons are
orbiting around the nucleus
1914 Bohr Energy Level model: electrons can
only have certain fixed energies; they can jump from a level to another one.
1926 Schrödinger
Electron cloud: Electrons don’t move in orbits (or in a set path). He stated that they move in waves, and they have no exact location.
1932 Chadwick Discovered the neutron
